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How to convert X/Y position to Canvas Left/Top properties when using ItemsControl

- by kshahar

I am trying to use a Canvas to display objects that have "world" location (rather than "screen" location). The canvas is defined like this: <Canvas Background="AliceBlue"> <ItemsControl Name="myItemsControl" ItemsSource="{Binding MyItems}"> <ItemsControl.ItemTemplate> <DataTemplate> <Canvas> <TextBlock Canvas.Left="{Binding WorldX}" Canvas.Top="{Binding WorldY}" Text="{Binding Text}" Width="Auto" Height="Auto" Foreground="Red" /> </Canvas> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> </Canvas> MyItem is defined like this: public class MyItem { public MyItem(double worldX, double worldY, string text) { WorldX = worldX; WorldY = worldY; Text = text; } public double WorldX { get; set; } public double WorldY { get; set; } public string Text { get; set; } } In addition, I have a method to convert between world and screen coordinates: Point worldToScreen(double worldX, double worldY) { // return screen coordinates using the canvas properties and an internal MapData object } With the current implementation, the items are positioned in the wrong location, because their location is not converted to screen coordinates. How can I apply the worldToScreen method on the MyItem objects before they are added to the canvas?

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What am I doing wrong with my ItemsControl & databinding?

- by Joel

I'm reworking my simple hex editor to practice using what I've recently learned about data binding in WPF. I'm not sure what I'm doing wrong here. As I understand it, for each byte in the collection "backend" (inherits from ObservableCollection), my ItemsControl should apply the DataTemplate under resources. This template is just a textbox with a binding to a value converter. So I'm expecting to see a row of textboxes, each containing a string representation of one byte. When I use this XAML, all I get is a single line of uneditable text, which as far as I can tell doesn't use a textbox. What am I doing wrong? I've pasted my XAML in below, with the irrelevant parts (Menu declaration, schema, etc) removed. <Window ...> <Window.Resources> <local:Backend x:Key="backend" /> <local:ByteConverter x:Key="byteConverter" /> <DataTemplate DataType="byte"> <TextBox Text="{Binding Converter={StaticResource byteConverter}}" /> </DataTemplate> </Window.Resources> <StackPanel> <ItemsControl ItemsSource="{Binding Source={StaticResource backend}}"> <ItemsControl.ItemsPanel> <ItemsPanelTemplate> <WrapPanel /> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> </ItemsControl> </StackPanel> </Window>

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Updating the foreground of a label on window active property-WPF

- by Deb

I have a label which shows the name of the window. I want to update the colour of the label on the IsActive property of the window using styles and triggers so that all the labels inheriting this style should exhibit the same property. Please can anyone suggest me how? I tried like this: <Style TargetType="{x:Type Label}" x:Key="HeaderLabel"> <Style.Triggers> <DataTrigger Binding="{Binding (Window.IsActive)}" Value="True"> <Setter Property="FontSize" Value="15"/> <Setter Property="FontWeight" Value="Bold"/> <Setter Property="FontFamily" Value="Arial"/> <Setter Property="Foreground" Value="Black"/> <Setter Property="HorizontalAlignment" Value="Left"/> </DataTrigger> <DataTrigger Binding="{Binding (Window.IsActive)}" Value="False"> <Setter Property="FontSize" Value="15"/> <Setter Property="FontWeight" Value="Bold"/> <Setter Property="FontFamily" Value="Arial"/> <Setter Property="Foreground" Value="White"/> <Setter Property="HorizontalAlignment" Value="Left"/> </DataTrigger> </Style.Triggers> </Style>

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GetLocalValueEnumerator() Not Returning All Properties

- by a_hardin

I am trying to perform validation in my WPF application using the solution in Detecting WPF Validation Errors. public static bool IsValid(DependencyObject parent) { // Validate all the bindings on the parent bool valid = true; LocalValueEnumerator localValues = parent.GetLocalValueEnumerator(); while (localValues.MoveNext()) { LocalValueEntry entry = localValues.Current; if (BindingOperations.IsDataBound(parent, entry.Property)) { Binding binding = BindingOperations.GetBinding(parent, entry.Property); foreach (ValidationRule rule in binding.ValidationRules) { ValidationResult result = rule.Validate(parent.GetValue(entry.Property), null); if (!result.IsValid) { BindingExpression expression = BindingOperations.GetBindingExpression(parent, entry.Property); System.Windows.Controls.Validation.MarkInvalid(expression, new ValidationError(rule, expression, result.ErrorContent, null)); valid = false; } } } } // Validate all the bindings on the children for (int i = 0; i != VisualTreeHelper.GetChildrenCount(parent); ++i) { DependencyObject child = VisualTreeHelper.GetChild(parent, i); if (!IsValid(child)) { valid = false; } } return valid; } The problem I am running into is that when I step through the code for a TextBox, I'm not getting the Text property. The only properties I get are "PageHeight", "Instance", and "UndoManagerInstance". Therefore, I can not Validate the rules for the binding on the TextBox. Does anyone have any idea why I wouldn't be getting the correct properties? Is there another way to force validaton on controls in WPF? I haven't been able to find anyone else who has had this problem. Update: The TextBoxes I am trying to validate are within a DataTemplate. I found that if I copy one of the TextBoxes and place it directly in the Window, I am able to get the data. Using Woodstock, I saw that the data source for the TextBoxes in the template is "ParentTemplate", but it's "Local" for the TextBox outside of the template. So, the question now is, how can I get the DependencyProperties for controls inside a DataTemplate?

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Observations in Migrating from JavaFX Script to JavaFX 2.0

- by user12608080

Observations in Migrating from JavaFX Script to JavaFX 2.0 Introduction Having been available for a few years now, there is a decent body of work written for JavaFX using the JavaFX Script language. With the general availability announcement of JavaFX 2.0 Beta, the natural question arises about converting the legacy code over to the new JavaFX 2.0 platform. This article reflects on some of the observations encountered while porting source code over from JavaFX Script to the new JavaFX API paradigm. The Application The program chosen for migration is an implementation of the Sudoku game and serves as a reference application for the book JavaFX – Developing Rich Internet Applications. The design of the program can be divided into two major components: (1) A user interface (ideally suited for JavaFX design) and (2) the puzzle generator. For the context of this article, our primary interest lies in the user interface. The puzzle generator code was lifted from a sourceforge.net project and is written entirely in Java. Regardless which version of the UI we choose (JavaFX Script vs. JavaFX 2.0), no code changes were required for the puzzle generator code. The original user interface for the JavaFX Sudoku application was written exclusively in JavaFX Script, and as such is a suitable candidate to convert over to the new JavaFX 2.0 model. However, a few notable points are worth mentioning about this program. First off, it was written in the JavaFX 1.1 timeframe, where certain capabilities of the JavaFX framework were as of yet unavailable. Citing two examples, this program creates many of its own UI controls from scratch because the built-in controls were yet to be introduced. In addition, layout of graphical nodes is done in a very manual manner, again because much of the automatic layout capabilities were in flux at the time. It is worth considering that this program was written at a time when most of us were just coming up to speed on this technology. One would think that having the opportunity to recreate this application anew, it would look a lot different from the current version. Comparing the Size of the Source Code An attempt was made to convert each of the original UI JavaFX Script source files (suffixed with .fx) over to a Java counterpart. Due to language feature differences, there are a small number of source files which only exist in one version or the other. The table below summarizes the size of each of the source files. JavaFX Script source file Number of Lines Number of Character JavaFX 2.0 Java source file Number of Lines Number of Characters ArrowKey.java 6 72 Board.fx 221 6831 Board.java 205 6508 BoardNode.fx 446 16054 BoardNode.java 723 29356 ChooseNumberNode.fx 168 5267 ChooseNumberNode.java 302 10235 CloseButtonNode.fx 115 3408 CloseButton.java 99 2883 ParentWithKeyTraversal.java 111 3276 FunctionPtr.java 6 80 Globals.java 20 554 Grouping.fx 8 140 HowToPlayNode.fx 121 3632 HowToPlayNode.java 136 4849 IconButtonNode.fx 196 5748 IconButtonNode.java 183 5865 Main.fx 98 3466 Main.java 64 2118 SliderNode.fx 288 10349 SliderNode.java 350 13048 Space.fx 78 1696 Space.java 106 2095 SpaceNode.fx 227 6703 SpaceNode.java 220 6861 TraversalHelper.fx 111 3095 Total 2,077 79,127 2531 87,800 A few notes about this table are in order: The number of lines in each file was determined by running the Unix ‘wc –l’ command over each file. The number of characters in each file was determined by running the Unix ‘ls –l’ command over each file. The examination of the code could certainly be much more rigorous. No standard formatting was performed on these files. All comments however were deleted. There was a certain expectation that the new Java version would require more lines of code than the original JavaFX script version. As evidenced by a count of the total number of lines, the Java version has about 22% more lines than its FX Script counterpart. Furthermore, there was an additional expectation that the Java version would be more verbose in terms of the total number of characters. In fact the preceding data shows that on average the Java source files contain fewer characters per line than the FX files. But that's not the whole story. Upon further examination, the FX Script source files had a disproportionate number of blank characters. Why? Because of the nature of how one develops JavaFX Script code. The object literal dominates FX Script code. Its not uncommon to see object literals indented halfway across the page, consuming lots of meaningless space characters. RAM consumption Not the most scientific analysis, memory usage for the application was examined on a Windows Vista system by running the Windows Task Manager and viewing how much memory was being consumed by the Sudoku version in question. Roughly speaking, the FX script version, after startup, had a RAM footprint of about 90MB and remained pretty much the same size. The Java version started out at about 55MB and maintained that size throughout its execution. What About Binding? Arguably, the most striking observation about the conversion from JavaFX Script to JavaFX 2.0 concerned the need for data synchronization, or lack thereof. In JavaFX Script, the primary means to synchronize data is via the bind expression (using the “bind” keyword), and perhaps to a lesser extent it’s “on replace” cousin. The bind keyword does not exist in Java, so for JavaFX 2.0 a Data Binding API has been introduced as a replacement. To give a feel for the difference between the two versions of the Sudoku program, the table that follows indicates how many binds were required for each source file. For JavaFX Script files, this was ascertained by simply counting the number of occurrences of the bind keyword. As can be seen, binding had been used frequently in the JavaFX Script version (and does not take into consideration an additional half dozen or so “on replace” triggers). The JavaFX 2.0 program achieves the same functionality as the original JavaFX Script version, yet the equivalent of binding was only needed twice throughout the Java version of the source code. JavaFX Script source file Number of Binds JavaFX Next Java source file Number of “Binds” ArrowKey.java 0 Board.fx 1 Board.java 0 BoardNode.fx 7 BoardNode.java 0 ChooseNumberNode.fx 11 ChooseNumberNode.java 0 CloseButtonNode.fx 6 CloseButton.java 0 CustomNodeWithKeyTraversal.java 0 FunctionPtr.java 0 Globals.java 0 Grouping.fx 0 HowToPlayNode.fx 7 HowToPlayNode.java 0 IconButtonNode.fx 9 IconButtonNode.java 0 Main.fx 1 Main.java 0 Main_Mobile.fx 1 SliderNode.fx 6 SliderNode.java 1 Space.fx 0 Space.java 0 SpaceNode.fx 9 SpaceNode.java 1 TraversalHelper.fx 0 Total 58 2 Conclusions As the JavaFX 2.0 technology is so new, and experience with the platform is the same, it is possible and indeed probable that some of the observations noted in the preceding article may not apply across other attempts at migrating applications. That being said, this first experience indicates that the migrated Java code will likely be larger, though not extensively so, than the original Java FX Script source. Furthermore, although very important, it appears that the requirements for data synchronization via binding, may be significantly less with the new platform.

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Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

- by Stephen.Walther

The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", “readwrite”); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title>  <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script>  <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div>  <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", "readwrite"); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

- by Stephen.Walther

The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title>  <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script>  <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div>  <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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The case of the phantom ADF developer (and other yarns)

- by Chris Muir

A few years of ADF experience means I see common mistakes made by different developers, some I regularly make myself. This post is designed to assist beginners to Oracle JDeveloper Application Development Framework (ADF) avoid a common ADF pitfall, the case of the phantom ADF developer [add Scooby-Doo music here]. ADF Business Components - triggers, default table values and instead of views. Oracle's JDeveloper tutorials help with the A-B-Cs of ADF development, typically built on the nice 'n safe demo schema provided by with the Oracle database such as the HR demo schema. However it's not too long until ADF beginners, having built up some confidence from learning with the tutorials and vanilla demo schemas, start building ADF Business Components based upon their own existing database schema objects. This is where unexpected problems can sneak in. The crime Developers may encounter a surprising error at runtime when editing a record they just created or updated and committed to the database, based on their own existing tables, namely the error: JBO-25014: Another user has changed the row with primary key oracle.jbo.Key[x] ...where X is the primary key value of the row at hand. In a production environment with multiple users this error may be legit, one of the other users has updated the row since you queried it. Yet in a development environment this error is just plain confusing. If developers are isolated in their own database, creating and editing records they know other users can't possibly be working with, or all the other developers have gone home for the day, how is this error possible? There are no other users? It must be the phantom ADF developer! [insert dramatic music here] The following picture is what you'll see in the Business Component Browser, and you'll receive a similar error message via an ADF Faces page: A false conclusion What can possibly cause this issue if it isn't our phantom ADF developer? Doesn't ADF BC implement record locking, locking database records when the row is modified in the ADF middle-tier by a user? How can our phantom ADF developer even take out a lock if this is the case? Maybe ADF has a bug, maybe ADF isn't implementing record locking at all? Shouldn't we see the error "JBO-26030: Failed to lock the record, another user holds the lock" as we attempt to modify the record, why do we see JBO-25014? : Let's verify that ADF is in fact issuing the correct SQL LOCK-FOR-UPDATE statement to the database. First we need to verify ADF's locking strategy. It is determined by the Application Module's jbo.locking.mode property. The default (as of JDev 11.1.1.4.0 if memory serves me correct) and recommended value is optimistic, and the other valid value is pessimistic. Next we need a mechanism to check that ADF is issuing the LOCK statements to the database. We could ask DBAs to monitor locks with OEM, but optimally we'd rather not involve overworked DBAs in this process, so instead we can use the ADF runtime setting –Djbo.debugoutput=console. At runtime this options turns on instrumentation within the ADF BC layer, which among a lot of extra detail displayed in the log window, will show the actual SQL statement issued to the database, including the LOCK statement we're looking to confirm. Setting our locking mode to pessimistic, opening the Business Components Browser of a JSF page allowing us to edit a record, say the CHARGEABLE field within a BOOKINGS record where BOOKING_NO = 1206, upon editing the record see among others the following log entries: [421] Built select: 'SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings'[422] Executing LOCK...SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings WHERE BOOKING_NO=:1 FOR UPDATE NOWAIT[423] Where binding param 1: 1206 As can be seen on line 422, in fact a LOCK-FOR-UPDATE is indeed issued to the database. Later when we commit the record we see: [441] OracleSQLBuilder: SAVEPOINT 'BO_SP'[442] OracleSQLBuilder Executing, Lock 1 DML on: BOOKINGS (Update)[443] UPDATE buf Bookings>#u SQLStmtBufLen: 210, actual=62[444] UPDATE BOOKINGS Bookings SET CHARGEABLE=:1 WHERE BOOKING_NO=:2[445] Update binding param 1: N[446] Where binding param 2: 1206[447] BookingsView1 notify COMMIT ... [448] _LOCAL_VIEW_USAGE_model_Bookings_ResourceTypesView1 notify COMMIT ... [449] EntityCache close prepared statement ....and as a result the changes are saved to the database, and the lock is released. Let's see what happens when we use the optimistic locking mode, this time to change the same BOOKINGS record CHARGEABLE column again. As soon as we edit the record we see little activity in the logs, nothing to indicate any SQL statement, let alone a LOCK has been taken out on the row. However when we save our records by issuing a commit, the following is recorded in the logs: [509] OracleSQLBuilder: SAVEPOINT 'BO_SP'[510] OracleSQLBuilder Executing doEntitySelect on: BOOKINGS (true)[511] Built select: 'SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings'[512] Executing LOCK...SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings WHERE BOOKING_NO=:1 FOR UPDATE NOWAIT[513] Where binding param 1: 1205[514] OracleSQLBuilder Executing, Lock 2 DML on: BOOKINGS (Update)[515] UPDATE buf Bookings>#u SQLStmtBufLen: 210, actual=62[516] UPDATE BOOKINGS Bookings SET CHARGEABLE=:1 WHERE BOOKING_NO=:2[517] Update binding param 1: Y[518] Where binding param 2: 1205[519] BookingsView1 notify COMMIT ... [520] _LOCAL_VIEW_USAGE_model_Bookings_ResourceTypesView1 notify COMMIT ... [521] EntityCache close prepared statement Again even though we're seeing the midtier delay the LOCK statement until commit time, it is in fact occurring on line 412, and released as part of the commit issued on line 419. Therefore with either optimistic or pessimistic locking a lock is indeed issued. Our conclusion at this point must be, unless there's the unlikely cause the LOCK statement is never really hitting the database, or the even less likely cause the database has a bug, then ADF does in fact take out a lock on the record before allowing the current user to update it. So there's no way our phantom ADF developer could even modify the record if he tried without at least someone receiving a lock error. Hmm, we can only conclude the locking mode is a red herring and not the true cause of our problem. Who is the phantom? At this point we'll need to conclude that the error message "JBO-25014: Another user has changed" is somehow legit, even though we don't understand yet what's causing it. This leads onto two further questions, how does ADF know another user has changed the row, and what's been changed anyway? To answer the first question, how does ADF know another user has changed the row, the Fusion Guide's section 4.10.11 How to Protect Against Losing Simultaneous Updated Data , that details the Entity Object Change-Indicator property, gives us the answer: At runtime the framework provides automatic "lost update" detection for entity objects to ensure that a user cannot unknowingly modify data that another user has updated and committed in the meantime. Typically, this check is performed by comparing the original values of each persistent entity attribute against the corresponding current column values in the database at the time the underlying row is locked. Before updating a row, the entity object verifies that the row to be updated is still consistent with the current state of the database. The guide further suggests to make this solution more efficient: You can make the lost update detection more efficient by identifying any attributes of your entity whose values you know will be updated whenever the entity is modified. Typical candidates include a version number column or an updated date column in the row.....To detect whether the row has been modified since the user queried it in the most efficient way, select the Change Indicator option to compare only the change-indicator attribute values. We now know that ADF BC doesn't use the locking mechanism at all to protect the current user against updates, but rather it keeps a copy of the original record fetched, separate to the user changed version of the record, and it compares the original record against the one in the database when the lock is taken out. If values don't match, be it the default compare-all-columns behaviour, or the more efficient Change Indicator mechanism, ADF BC will throw the JBO-25014 error. This leaves one last question. Now we know the mechanism under which ADF identifies a changed row, what we don't know is what's changed and who changed it? The real culprit What's changed? We know the record in the mid-tier has been changed by the user, however ADF doesn't use the changed record in the mid-tier to compare to the database record, but rather a copy of the original record before it was changed. This leaves us to conclude the database record has changed, but how and by who? There are three potential causes: Database triggers The database trigger among other uses, can be configured to fire PLSQL code on a database table insert, update or delete. In particular in an insert or update the trigger can override the value assigned to a particular column. The trigger execution is actioned by the database on behalf of the user initiating the insert or update action. Why this causes the issue specific to our ADF use, is when we insert or update a record in the database via ADF, ADF keeps a copy of the record written to the database. However the cached record is instantly out of date as the database triggers have modified the record that was actually written to the database. Thus when we update the record we just inserted or updated for a second time to the database, ADF compares its original copy of the record to that in the database, and it detects the record has been changed – giving us JBO-25014. This is probably the most common cause of this problem. Default values A second reason this issue can occur is another database feature, default column values. When creating a database table the schema designer can define default values for specific columns. For example a CREATED_BY column could be set to SYSDATE, or a flag column to Y or N. Default values are only used by the database when a user inserts a new record and the specific column is assigned NULL. The database in this case will overwrite the column with the default value. As per the database trigger section, it then becomes apparent why ADF chokes on this feature, though it can only specifically occur in an insert-commit-update-commit scenario, not the update-commit-update-commit scenario. Instead of trigger views I must admit I haven't double checked this scenario but it seems plausible, that of the Oracle database's instead of trigger view (sometimes referred to as instead of views). A view in the database is based on a query, and dependent on the queries complexity, may support insert, update and delete functionality to a limited degree. In order to support fully insertable, updateable and deletable views, Oracle introduced the instead of view, that gives the view designer the ability to not only define the view query, but a set of programmatic PLSQL triggers where the developer can define their own logic for inserts, updates and deletes. While this provides the database programmer a very powerful feature, it can cause issues for our ADF application. On inserting or updating a record in the instead of view, the record and it's data that goes in is not necessarily the data that comes out when ADF compares the records, as the view developer has the option to practically do anything with the incoming data, including throwing it away or pushing it to tables which aren't used by the view underlying query for fetching the data. Readers are at this point reminded that this article is specifically about how the JBO-25014 error occurs in the context of 1 developer on an isolated database. The article is not considering how the error occurs in a production environment where there are multiple users who can cause this error in a legitimate fashion. Assuming none of the above features are the cause of the problem, and optimistic locking is turned on (this error is not possible if pessimistic locking is the default mode *and* none of the previous causes are possible), JBO-25014 is quite feasible in a production ADF application if 2 users modify the same record. At this point under project timelines pressure, the obvious fix for developers is to drop both database triggers and default values from the underlying tables. However we must be careful that these legacy constructs aren't used and assumed to be in place by other legacy systems. Dropping the database triggers or default value that the existing Oracle Forms applications assumes and requires to be in place could cause unexpected behaviour and bugs in the Forms application. Proficient software engineers would recognize such a change may require a partial or full regression test of the existing legacy system, a potentially costly and timely exercise, not ideal. Solving the mystery once and for all Luckily ADF has built in functionality to deal with this issue, though it's not a surprise, as Oracle as the author of ADF also built the database, and are fully aware of the Oracle database's feature set. At the Entity Object attribute level, the Refresh After Insert and Refresh After Update properties. Simply selecting these instructs ADF BC after inserting or updating a record to the database, to expect the database to modify the said attributes, and read a copy of the changed attributes back into its cached mid-tier record. Thus next time the developer modifies the current record, the comparison between the mid-tier record and the database record match, and JBO-25014: Another user has changed" is no longer an issue. [Post edit - as per the comment from Oracle's Steven Davelaar below, as he correctly points out the above solution will not work for instead-of-triggers views as it relies on SQL RETURNING clause which is incompatible with this type of view] Alternatively you can set the Change Indicator on one of the attributes. This will work as long as the relating column for the attribute in the database itself isn't inadvertently updated. In turn you're possibly just masking the issue rather than solving it, because if another developer turns the Change Indicator back on the original issue will return.

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WPF, how can I optimize lines and circles drawing ?

- by Aurélien Ribon

Hello ! I am developping an application where I need to draw a graph on the screen. For this purpose, I use a Canvas and I put Controls on it. An example of such a draw as shown in the app can be found here : http://free0.hiboox.com/images/1610/d82e0b7cc3521071ede601d3542c7bc5.png It works fine for simple graphs, but I also want to be able to draw very large graphs (hundreds of nodes). And when I try to draw a very large graph, it takes a LOT of time to render. My problem is that the code is not optimized at all, I just wanted it to work. Until now, I have a Canvas on the one hand, and multiple Controls on the other hands. Actually, circles and lines are listed in collections, and for each item of these collections, I use a ControlTemplate, defining a red circle, a black circle, a line, etc. Here is an example, the definition of a graph circle :  <Style TargetType="{x:Type flow.elements:DisplayNode}"> <Setter Property="Canvas.Left" Value="{Binding X, RelativeSource={RelativeSource Self}}" /> <Setter Property="Canvas.Top" Value="{Binding Y, RelativeSource={RelativeSource Self}}" /> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type flow.elements:DisplayNode}">  <Grid x:Name="grid" Margin="-30,-30,0,0"> <Ellipse x:Name="selectionEllipse" StrokeThickness="0" Width="60" Height="60" Opacity="0" IsHitTestVisible="False"> <Ellipse.Fill> <RadialGradientBrush> <GradientStop Color="Black" Offset="0.398" /> <GradientStop Offset="1" /> </RadialGradientBrush> </Ellipse.Fill> </Ellipse> <Ellipse Stroke="Black" Width="30" Height="30" x:Name="ellipse"> <Ellipse.Fill> <LinearGradientBrush EndPoint="0,1"> <GradientStop Offset="0" Color="White" /> <GradientStop Offset="1.5" Color="LightGray" /> </LinearGradientBrush> </Ellipse.Fill> </Ellipse> <TextBlock x:Name="tblock" Text="{Binding NodeName, RelativeSource={RelativeSource Mode=TemplatedParent}}" Foreground="Black" VerticalAlignment="Center" HorizontalAlignment="Center" FontSize="10.667" /> </Grid>  <ControlTemplate.Triggers>  <MultiTrigger> <MultiTrigger.Conditions> <Condition Property="SkinMode" Value="NODETYPE" /> <Condition Property="NodeType" Value="DATAINPUT" /> </MultiTrigger.Conditions> <Setter TargetName="tblock" Property="Foreground" Value="White" /> <Setter TargetName="ellipse" Property="Fill"> <Setter.Value> <LinearGradientBrush EndPoint="0,1"> <GradientStop Offset="-0.5" Color="White" /> <GradientStop Offset="1" Color="Black" /> </LinearGradientBrush> </Setter.Value> </Setter> </MultiTrigger>  <MultiTrigger> <MultiTrigger.Conditions> <Condition Property="SkinMode" Value="NODETYPE" /> <Condition Property="NodeType" Value="DATAOUTPUT" /> </MultiTrigger.Conditions> <Setter TargetName="tblock" Property="Foreground" Value="White" /> <Setter TargetName="ellipse" Property="Fill"> <Setter.Value> <LinearGradientBrush EndPoint="0,1"> <GradientStop Offset="-0.5" Color="White" /> <GradientStop Offset="1" Color="Black" /> </LinearGradientBrush> </Setter.Value> </Setter> </MultiTrigger> ....... THERE IS A TOTAL OF 7 MULTITRIGGERS ....... </ControlTemplate.Triggers> </ControlTemplate> </Setter.Value> </Setter> </Style> Also, the lines are drawn using the Line Control.  <Style TargetType="{x:Type flow.elements:DisplayLink}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type flow.elements:DisplayLink}">  <Line X1="{Binding X1, RelativeSource={RelativeSource TemplatedParent}}" X2="{Binding X2, RelativeSource={RelativeSource TemplatedParent}}" Y1="{Binding Y1, RelativeSource={RelativeSource TemplatedParent}}" Y2="{Binding Y2, RelativeSource={RelativeSource TemplatedParent}}" Stroke="Gray" StrokeThickness="2" x:Name="line" />  <ControlTemplate.Triggers>  <MultiTrigger> <MultiTrigger.Conditions> <Condition Property="SkinMode" Value="BRANCHTYPE" /> <Condition Property="BranchType" Value="ASSERTION" /> </MultiTrigger.Conditions> <Setter TargetName="line" Property="Stroke" Value="#E0E0E0" /> </MultiTrigger> </ControlTemplate.Triggers> </ControlTemplate> </Setter.Value> </Setter> </Style> So, I need your advices. How can I drastically improve the rendering performances ? Should I define each MultiTrigger circle rendering possibility in its own ControlTemplate instead ? Is there a better line drawing technique ? Should I open a DrawingContext and draw everything in one control, instead of having hundreds of controls ?

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WCF Service returning 400 error: The body of the message cannot be read because it is empty

- by Josh

I have a WCF service that is causing a bit of a headache. I have tracing enabled, I have an object with a data contract being built and passed in, but I am seeing this error in the log: <TraceData> <DataItem> <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Error"> <TraceIdentifier>http://msdn.microsoft.com/en-US/library/System.ServiceModel.Diagnostics.ThrowingException.aspx</TraceIdentifier> <Description>Throwing an exception.</Description> <AppDomain>efb0d0d7-1-129315381593520544</AppDomain> <Exception> <ExceptionType>System.ServiceModel.ProtocolException, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType> <Message>There is a problem with the XML that was received from the network. See inner exception for more details.</Message> <StackTrace> at System.ServiceModel.Channels.HttpRequestContext.CreateMessage() at System.ServiceModel.Channels.HttpChannelListener.HttpContextReceived(HttpRequestContext context, Action callback) at System.ServiceModel.Activation.HostedHttpTransportManager.HttpContextReceived(HostedHttpRequestAsyncResult result) at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.HandleRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.BeginRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.OnBeginRequest(Object state) at System.Runtime.IOThreadScheduler.ScheduledOverlapped.IOCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped) at System.Runtime.Fx.IOCompletionThunk.UnhandledExceptionFrame(UInt32 error, UInt32 bytesRead, NativeOverlapped* nativeOverlapped) at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP) </StackTrace> <ExceptionString> System.ServiceModel.ProtocolException: There is a problem with the XML that was received from the network. See inner exception for more details. ---&gt; System.Xml.XmlException: The body of the message cannot be read because it is empty. --- End of inner exception stack trace --- </ExceptionString> <InnerException> <ExceptionType>System.Xml.XmlException, System.Xml, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType> <Message>The body of the message cannot be read because it is empty.</Message> <StackTrace> at System.ServiceModel.Channels.HttpRequestContext.CreateMessage() at System.ServiceModel.Channels.HttpChannelListener.HttpContextReceived(HttpRequestContext context, Action callback) at System.ServiceModel.Activation.HostedHttpTransportManager.HttpContextReceived(HostedHttpRequestAsyncResult result) at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.HandleRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.BeginRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.OnBeginRequest(Object state) at System.Runtime.IOThreadScheduler.ScheduledOverlapped.IOCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped) at System.Runtime.Fx.IOCompletionThunk.UnhandledExceptionFrame(UInt32 error, UInt32 bytesRead, NativeOverlapped* nativeOverlapped) at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP) </StackTrace> <ExceptionString>System.Xml.XmlException: The body of the message cannot be read because it is empty.</ExceptionString> </InnerException> </Exception> </TraceRecord> </DataItem> </TraceData> So, here is my service interface: [ServiceContract] public interface IRDCService { [OperationContract] Response<Customer> GetCustomer(CustomerRequest request); [OperationContract] Response<Customer> GetSiteCustomers(CustomerRequest request); } And here is my service instance public class RDCService : IRDCService { ICustomerService customerService; public RDCService() { //We have to locate the instance from structuremap manually because web services *REQUIRE* a default constructor customerService = ServiceLocator.Locate<ICustomerService>(); } public Response<Customer> GetCustomer(CustomerRequest request) { return customerService.GetCustomer(request); } public Response<Customer> GetSiteCustomers(CustomerRequest request) { return customerService.GetSiteCustomers(request); } } The configuration for the web service (server side) looks like this: <system.serviceModel> <diagnostics> <messageLogging logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" /> </diagnostics> <services> <service behaviorConfiguration="MySite.Web.Services.RDCServiceBehavior" name="MySite.Web.Services.RDCService"> <endpoint address="http://localhost:27433" binding="wsHttpBinding" contract="MySite.Common.Services.Web.IRDCService"> <identity> <dns value="localhost:27433" /> </identity> </endpoint> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" /> </service> </services> <behaviors> <serviceBehaviors> <behavior name="MySite.Web.Services.RDCServiceBehavior">  <serviceMetadata httpGetEnabled="true"/>  <serviceDebug includeExceptionDetailInFaults="true"/> <dataContractSerializer maxItemsInObjectGraph="6553600" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> Here is what my request object looks like [DataContract] public class CustomerRequest : RequestBase { [DataMember] public int Id { get; set; } [DataMember] public int SiteId { get; set; } } And the RequestBase: [DataContract] public abstract class RequestBase : IRequest { #region IRequest Members [DataMember] public int PageSize { get; set; } [DataMember] public int PageIndex { get; set; } #endregion } And my IRequest interface public interface IRequest { int PageSize { get; set; } int PageIndex { get; set; } } And I have a wrapper class around my service calls. Here is the class. public class MyService : IMyService { IRDCService service; public MyService() { //service = new MySite.RDCService.RDCServiceClient(); EndpointAddress address = new EndpointAddress(APISettings.Default.ServiceUrl); BasicHttpBinding binding = new BasicHttpBinding(BasicHttpSecurityMode.None); binding.TransferMode = TransferMode.Streamed; binding.MaxBufferSize = 65536; binding.MaxReceivedMessageSize = 4194304; ChannelFactory<IRDCService> factory = new ChannelFactory<IRDCService>(binding, address); service = factory.CreateChannel(); } public Response<Customer> GetCustomer(CustomerRequest request) { return service.GetCustomer(request); } public Response<Customer> GetSiteCustomers(CustomerRequest request) { return service.GetSiteCustomers(request); } } and finally, the response object. [DataContract] public class Response<T> { [DataMember] public IEnumerable<T> Results { get; set; } [DataMember] public int TotalResults { get; set; } [DataMember] public int PageIndex { get; set; } [DataMember] public int PageSize { get; set; } [DataMember] public RulesException Exception { get; set; } } So, when I build my CustomerRequest object and pass it in, for some reason it's hitting the server as an empty request. Any ideas why? I've tried upping the object graph and the message size. When I debug it stops in the wrapper class with the 400 error. I'm not sure if there is a serialization error, but considering the object contract is 4 integer properties I can't imagine it causing an issue.

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Using Private Browsing keyboard shortcut with Firefox and Vimperator

- by perlwle

I am using Firefox 15.0 on OS X Mountain Lion alongside with vimperator. Note that I am using a Windows keyboard. CtrlP is for moving focus to left tab in vimperator. However, the latest Firefox has also CtrlP to enable private browsing. I looked for private browsing with FF "Customizable Shortcuts" addon but there is only CommandShiftP binding associated to it. How can the CtrlP private browsing binding be turned off?

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Duplicate IIS web site with Web Deploy

- by gsantovena

I have a Win2008 server with IIS 7 and I want to duplicate one web site and just change the binding port and the application pool that is using, so I will have 2 web sites (locally or remote) with same configuration but listening on different ports. Is there a way to do this with web deploy tool ir order to deploy locally and remotely this unique web site and change the binding ports in the destination?

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Disable default Gnome Shell Super Key Mapping

- by soares

Gnome Shell by default uses the Super (Windows) key to display the activities overview. But I'd prefer to use the Super key to invoke Synapse. Right now I have to press Super+Super+Spacebar in order to invoke Synapse which is annoying (Super+Spacebar is the binding to invoke Synapse). Is there any way to remove the default Gnome Shell mapping? In the keyboard shortcuts system settings, only the Alt+F1 binding appears for the activities overview action.

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Why web application on https stops working after windows update?

- by Rychu

On Windows Server 2008 R2 I have several web applications on IIS7. One of these applications has https binding with SSL certificate. However after every windows update this one application stops working. Browser says that server is unavailable. It starts working again when I simply open IIS manager, select that https binding, click edit and without changing anything click OK. Why is this happening?

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how to enable WCF Session with wsHttpBidning with Transport only Security

- by Mubashar Ahmad

Dear Devs I have a WCF Service currently deployed with basicHttpBindings and SSL enabled. But now i need to enable wcf sessions(not asp sessions) so i moved service to wsHttpBidnings but sessions are not enabled I have set [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)] But when i set SessionMode=SessionMode.Required on service contract it says Contract requires Session, but Binding 'WSHttpBinding' doesn't support it or isn't configured properly to support it. following is the definition of WSHttpBinding <wsHttpBinding> <binding name="wsHttpBinding"> <readerQuotas maxStringContentLength="10240" /> <reliableSession enabled="false" /> <security mode="Transport"> <transport clientCredentialType="None"> <extendedProtectionPolicy policyEnforcement="Never" /> </transport> </security> </binding> </wsHttpBinding> please help me with this

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WinForms (C#) Databinding Object to Checkbox.Checked Property

- by Trevor Sullivan

Hello, I'm writing a WinForms app, and am trying to bind a boolean property on a .NET object to a Checkbox's "checked" property. I am successfully creating the binding, but when I change the source property's value from false to true (I have a button that toggles it), the checkbox's "checked" property does not reflect that change. if (chkPreRun.DataBindings["Checked"] == null) { Debug.WriteLine("Adding chkPreRun databinding"); Binding _binding = chkPreRun.DataBindings.Add("Checked", NwmConfig, "PreRun") // Added this just to ensure that these were being set properly _binding.DataSourceUpdateMode = DataSourceUpdateMode.OnPropertyChanged; _binding.ControlUpdateMode = ControlUpdateMode.OnPropertyChanged; } I am able to successfully bind the text property to the value of a TextBox, for example. I'm not sure what I'm missing while binding to the "Checked" property, however. Cheers, Trevor

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WPF Custom Buttons below ListBox Items

- by Ryan

WPF Experts - I am trying to add buttons below my custom listbox and also have the scroll bar go to the bottom of the control. Only the items should move and not the buttons. I was hoping for some guidance on the best way to achieve this. I was thinking the ItemsPanelTemplate needed to be modified but was not certain. Thanks My code is below  <LinearGradientBrush x:Key="GotFocusStyle" EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.GradientStops> <GradientStop Color="Black" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF002F5C" Offset="0.5"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush>  <LinearGradientBrush x:Key="MouseOverFocusStyle" StartPoint="0,0" EndPoint="0,1"> <LinearGradientBrush.GradientStops> <GradientStop Color="#FF013B73" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF014A8F" Offset="0.5"/> <GradientStop Color="#FF003363" Offset="1"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush>  <LinearGradientBrush x:Key="LostFocusStyle" EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush>  <SolidColorBrush x:Key="ListItemHighlight" Color="#FFE38E27" />  <SolidColorBrush x:Key="ListItemUnHighlight" Color="#FF6FB8FD" /> <Style TargetType="ListBoxItem"> <EventSetter Event="GotFocus" Handler="ListItem_GotFocus"></EventSetter> <EventSetter Event="LostFocus" Handler="ListItem_LostFocus"></EventSetter> </Style> <DataTemplate x:Key="CustomListData" DataType="{x:Type ListBoxItem}"> <Border BorderBrush="Black" BorderThickness="1" Margin="-2,0,0,-1"> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBoxItem}}, Path=ActualWidth}" /> </Grid.ColumnDefinitions> <Label VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="{StaticResource ListItemUnHighlight}" FontSize="24" Tag="{Binding .}" Grid.Column="0" MinHeight="55" Cursor="Hand" FontFamily="Arial" FocusVisualStyle="{x:Null}" KeyboardNavigation.TabNavigation="None" Background="{StaticResource LostFocusStyle}" MouseMove="ListItem_MouseOver" > <Label.ContextMenu> <ContextMenu Name="editMenu"> <MenuItem Header="Edit"/> </ContextMenu> </Label.ContextMenu> <TextBlock Text="{Binding .}" Margin="15,0,40,0" TextWrapping="Wrap"></TextBlock> </Label> <Image Tag="{Binding .}" Source="{Binding}" Margin="260,0,0,0" Grid.Column="1" Stretch="None" Width="16" Height="22" HorizontalAlignment="Center" VerticalAlignment="Center" /> </Grid> </Border> </DataTemplate> </Window.Resources> <Window.DataContext> <ObjectDataProvider ObjectType="{x:Type local:ImageLoader}" MethodName="LoadImages" /> </Window.DataContext> <ListBox ItemsSource="{Binding}" Width="320" Background="#FF021422" BorderBrush="#FF1C4B79" > <ListBox.Resources> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}">Transparent</SolidColorBrush> <Style TargetType="{x:Type ListBox}"> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" /> <Setter Property="ItemTemplate" Value="{StaticResource CustomListData }" /> </Style> </ListBox.Resources> </ListBox>

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WPF ListView column auto sizing

- by Diego Mijelshon

Let's say I have the following ListView: <ListView ScrollViewer.VerticalScrollBarVisibility="Auto"> <ListView.View> <GridView> <GridViewColumn Header="Something" DisplayMemberBinding="{Binding Path=ShortText}" /> <GridViewColumn Header="Description" DisplayMemberBinding="{Binding Path=VeryLongTextWithCRs}" /> <GridViewColumn Header="Something Else" DisplayMemberBinding="{Binding Path=AnotherShortText}" /> </GridView> </ListView.View> </ListView> I'd like the short text columns to always fit in the screen, and the long text column to use the remaining space, word-wrapping if necessary. Is that possible?

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Strange exception when connecting to a WCF service via a proxy server

- by Slauma

The exception "This operation is not supported for a relative URI." occurs in the following situation: I have a WCF service: [ServiceContract(ProtectionLevel=ProtectionLevel.None)] public interface IMyService { [OperationContract] [FaultContract(typeof(MyFault))] List<MyDto> MyOperation(int param); // other operations } public class MyService : IMyService { public List<MyDto> MyOperation(int param) { // Do the business stuff and return a list of MyDto } // other implementations } MyFault and MyDto are two very simple classes marked with [DataContract] attribute and each only having three [DataMember] of type string, int and int?. This service is hosted in IIS 7.0 on a Win 2008 Server along with an ASP.NET application. I am using an SVC file MyService.svc which is located directly in the root of the web site. The service configuration in web.config is the following: <system.serviceModel> <services> <service name="MyServiceLib.MyService"> <endpoint address="" binding="wsHttpBinding" bindingConfiguration="wsHttpBindingConfig" contract="MyServiceLib.IMyService" /> </service> </services> <bindings> <wsHttpBinding> <binding name="wsHttpBindingConfig"> <security mode="None"> <transport clientCredentialType="None" /> </security> </binding> </wsHttpBinding> </bindings> <behaviors> <serviceBehaviors> <behavior> <serviceMetadata httpGetEnabled="false"/> <serviceDebug includeExceptionDetailInFaults="false" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> This seems to work so far as I can enter the address http://www.domain.com/MyService.svc in a browser and get the "This is a Windows Communication Foundation Service"-Welcome page. One of the clients consuming the service is a console application: MyServiceClient aChannel = new MyServiceClient("WSHttpBinding_IMyService"); List<MyDto> aMyDtoList = aChannel.MyOperation(1); It has the following configuration: <system.serviceModel> <bindings> <wsHttpBinding> <binding name="WSHttpBinding_IMyService" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="true" transactionFlow="false" hostNameComparisonMode="StrongWildcard" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="false" proxyAddress="10.20.30.40:8080" allowCookies="false"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" /> <security mode="None"> <transport clientCredentialType="Windows" proxyCredentialType="None" realm="" /> <message clientCredentialType="Windows" negotiateServiceCredential="true" /> </security> </binding> </wsHttpBinding> </bindings> <client> <endpoint address="http://www.domain.com/MyService.svc" binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IMyService" contract="MyService.IMyService" name="WSHttpBinding_IMyService" /> </client> </system.serviceModel> When I run this application at a production server at a customer site calling aChannel.MyOperation(1) throws the following exception: This operation is not supported for a relative URI. When I run this client application on my development PC with exactly the same config, with the exception that I remove proxyAddress="10.20.30.40:8080" from the bindings the operation works without problems. Now I really don't know what specifying a proxy server address might have to do with absolute or relative URIs. The use of the proxy server or not is the only difference I can see when running the client on the production or on the development machine. Does someone have an idea what this exception might mean in this context and how possibly to solve the problem? Thank you in advance for help!

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Cannot bind text field to selected item in JTable in NetBeans

- by titaniumdecoy

I am trying to use NetBeans to bind a JTextField to the selected element of a JTable. The JTable gets its data from an AbstractTableModel subclass which returns Cow objects. At present, each Cow object is displayed as a string through its toString method. The binding seems obvious but does not work; the bound value of the text field is always null. I bound the text property of the JTextField in NetBeans to: flowTable[${selectedElement.prefix}] This produces the following line of generated code: org.jdesktop.beansbinding.Binding binding = org.jdesktop.beansbinding.Bindings.createAutoBinding( org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ_WRITE, flowTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement.prefix}"), courseNameTextField, org.jdesktop.beansbinding.BeanProperty.create("text")); What am I doing wrong?

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Trying to run WCF web service on non-domain VM, Security Errors

- by NealWalters

Am I in a Catch-22 situation here? My goal is to take a WCF service that I inherited, and run it on a VM and test it by calling it from my desktop PC. The VM is in a workgroup, and not in the company's domain. Basically, we need more test environments, ideally one per developer (we may have 2 to 4 people that need this). Thus the idea of the VM was that each developer could have his own web server that somewhat matches or real environment (where we actually have two websites, an external/exposed and internal). [Using VS2010 .NET 4.0] In the internal service, each method was decorated with this attribute: [OperationBehavior(Impersonation = ImpersonationOption.Required)] I'm still researching why this was needed. I think it's because a webapp calls the "internal" service, and either a) we need the credentials of the user, or b) we may doing some PrinciplePermission.Demands to see if the user is in a group. My interest is creating some ConsoleTest programs or UnitTest programs. I changed to allowed like this: [OperationBehavior(Impersonation = ImpersonationOption.Allowed)] because I was getting this error in trying to view the .svc in the browser: The contract operation 'EditAccountFamily' requires Windows identity for automatic impersonation. A Windows identity that represents the caller is not provided by binding ('WSHttpBinding','http://tempuri.org/') for contract ('IAdminService','http://tempuri.org/'. I don't get that error with the original bindings look like this: However, I believe I need to turn off this security since the web service is not on the domain. I tend to get these errors in the client: 1) The request for security token could not be satisfied because authentication failed - as an InnerException of "SecurityNegotiation was unhandled". or 2) The caller was not authenticated by the service as an InnerException of "SecurityNegotiation was unhandled". So can I create some configuration of code and web.config that will allow each developer to work on his own VM? Or must I join the VM to the domain? The number of permutations seems near endless. I've started to create a Word.doc that says what to do with each error, but now I'm in the catch-22 where I'm stuck. Thanks, Neal Server Bindings: <bindings> <wsHttpBinding> <binding name="wsHttpEndpointBinding" maxBufferPoolSize="2147483647" maxReceivedMessageSize="500000000"> <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />  <security> <message clientCredentialType="Windows" /> </security> </binding> </wsHttpBinding> </bindings> <behaviors> <serviceBehaviors> <behavior name="ABC.AdminService.AdminServiceBehavior">  <serviceMetadata httpGetEnabled="true" />  <serviceDebug includeExceptionDetailInFaults="true" /> <serviceCredentials> </serviceCredentials>  <serviceAuthorization principalPermissionMode="UseWindowsGroups" impersonateCallerForAllOperations="true" /> </behavior> <behavior name="ABC.AdminService.IAdminServiceTransportBehavior">  <serviceMetadata httpGetEnabled="true" />  <serviceDebug includeExceptionDetailInFaults="false" /> <serviceCredentials> <clientCertificate> <authentication certificateValidationMode="PeerTrust" /> </clientCertificate> <serviceCertificate findValue="WCfServer" storeLocation="LocalMachine" storeName="My" x509FindType="FindBySubjectName" /> </serviceCredentials> </behavior> </serviceBehaviors> </behaviors> <serviceHostingEnvironment multipleSiteBindingsEnabled="true" /> CLIENT: <system.serviceModel> <bindings> <wsHttpBinding> <binding name="WSHttpBinding_IAdminService" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true" allowCookies="false"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" /> <security mode="Message"> <transport clientCredentialType="Windows" proxyCredentialType="None" realm="" /> <message clientCredentialType="Windows" negotiateServiceCredential="true" algorithmSuite="Default" /> </security> </binding> </wsHttpBinding> </bindings> <client> <endpoint address="http://192.168.159.132/EC_AdminService/AdminService.svc" binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IAdminService" contract="svcRef.IAdminService" name="WSHttpBinding_IAdminService"> <identity> <dns value="localhost" /> </identity> </endpoint> </client> </system.serviceModel>

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How to configure maximum number of channels in WCF?

- by Hemant

Consider following code which calls a calculator service: static void Main (string[] args) { for (int i = 0; i < 32; i++) { ThreadPool.QueueUserWorkItem (o => { var client = new CalcServiceClient (); client.Open (); while (true) { var sum = client.Add (2, 3); } }); } Console.ReadLine (); } If I use TCP binding then maximum 32 connections are opened but if I use HTTP binding, only 2 TCP connections are opened. How can I configure the maximum number of connections that can be opened using HTTP binding?

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WPF listbox : problem with selection

- by KiTe

Hello. In my XAML file, I have a ListBox declared like this : <ListBox x:Name="lstDeck" Height="280" ItemsSource="{Binding Path=Deck}" > <ListBox.ItemTemplate> <DataTemplate> <ListBoxItem Content="{Binding}" /> </DataTemplate> </ListBox.ItemTemplate> </ListBox> In my view model, Deck is an ObservableCollection, so that binding directly displays the content of my collection. But when I have several value that hold the same value (for example "10" six times), the selection in the ListBox has a weird behaviour : it select 2-3 elements instead of the only the one on which I clicked. Moreover, when I click to another listBoxItem, it doesn't unfocus the previous selected one. Then it is impossible to see which item is actually selected, and impossible to get the SelectedIndex value. Has someone an idea?

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Is there any event fired when a DataTemplate has been initiated in WPF?

- by Shimmy

Hello! Take a look at the following xaml: <ListBox ItemsSource="{Binding}"> <ListBox.Resources> <CollectionViewSource x:Key="CVS"/> </ListBox.Resources> <ListBox.DataTemplate> <DataTemplate OnBinding="myBinding"> <ListBox DataContext="{StaticResource CVS}" ItemsSource="{Binding}" /> </DataTemplate> </ListBox.DataTemplate> </ListBox> So I can handle the binding and manually retrieve the CVS and set its Source property to my custom stuff according to the DataTemplate's DataContext. Or else there is a different way in doing it. Any ideas are welcommed!

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Choice of a deleted element at ListBox control

- by Neir0

Hi I have created a listbox control with following DataTemplate <DataTemplate x:Key="lb_Itemtemplate"> <DockPanel> <TextBlock Text="{Binding}" DockPanel.Dock="Left" /> <Button DockPanel.Dock="Right" Template="{StaticResource ButtonTemplate }" Width="20" Margin=" 0,1,1,10" >Delete </Button> <Button DockPanel.Dock="Right" Template="{StaticResource ButtonTemplate }" Width="20" Margin="0,1,1,10" >Highlight </Button> </DockPanel> </DataTemplate> <ListBox Name="listBox1" Grid.Column="0" Grid.Row="1" DataContext="{Binding ElementName=cb_fields, Path=SelectedItem}" ItemsSource="{Binding Path=PositiveXPathExpressions}" ItemTemplate="{StaticResource lb_Itemtemplate}" /> I want to delete element from "PositiveXPathExpressions" collection when user clicked on button "delete" but How i can decide which element i must to delete?

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