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  • How do you know when you should change the programming domain you're working in?

    - by thecoop
    I've recently become one of the most senior developers in one division of the company, and am generally the 'go-to' guy about questions in the problem domain the division works in, however I feel I'm not learning anything new. To continue to learn new things I would have to change division and work on something competely different, but then my current domain knowledge would be useless & I would start off with knowing nothing again. Obviously, this is quite a large decision & I'm hesitant to lost my 'status'; and the knowledge I do have would be useless. How do you know when you should change the programming domain you work in?

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  • What web application is recommended when programming in Java for beginners?

    - by user1710260
    I am a beginner (almost no knowledge) to web applications. I have been programming in Java for about a year now. I have being doing some research on the different frameworks that are available and I want to find which one is right for me. From what I found: Play, Stripes, and Spring are good choices for beginners, but how can I compare these frameworks together. What is it that I need to look for when comparing them? My project that I am starting to work on is similar to an App Store. Basically an info site on different apps. Any advise will be appreciated.

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  • What is the sense of "Feature Oriented Programming" (FOP) in C++, and would it make sense in Java an

    - by ivan_ivanovich_ivanoff
    Hello! Sadly, I can't remember where I read it, but... ...in C++ you can derive a class from a template parameter. Im pretty sure it was called Feature Oriented Programming (FOP) and meant to be somehow useful. It was something like: template <class T> class my_class : T { // some very useful stuff goes here ;) } My questions about this: What is the sense of such pattern? Since this it not possible in Java / C#, how this pattern is achieved in these languages? Can it be expected to be implemented in Java / C# one day? (Well, first Java would need to get rid of type erasure) EDIT: I'm really not talking about generics in Java / C# (where you can't derive a class from a generic type parameter)

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  • How do people deal with mental plateaus in programming?

    - by ggfan
    Please excuse if this isn't the right type of question to ask here on SO. For the past few days, I just can't seem to get any quality programming done. I feel in the slumps when doing work and just can't concentrate. I also do happen to be learning a new skill(PHP framework) and I think that is the main reason why I feel I can't do anything. Are there anything you all do to "recharge" the brain and get back on track? Possible activites: 1. get away from the PC for a few days

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  • [C# n MySQL] Creating a database using Connector/NET Programming?

    - by yeeen
    How to create a database using connector/net programming? How come the following doesn't work? string connStr = "server=localhost;user=root;port=3306;password=mysql;"; MySqlConnection conn = new MySqlConnection(connStr); MySqlCommand cmd; string s0; try { conn.Open(); s0 = "CREATE DATABASE IF NOT EXISTS `hello`;"; cmd = new MySqlCommand(s0, conn); conn.Close(); } catch (Exception e) { Console.WriteLine(e.ToString()); }

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  • While programming, what to do when facing with a seemingly unsolvable situation with a time limit?

    - by Ersan Tasan
    This is not a technical question, but rather a social and methodical one. I am a computer sciences student and I usually have really tough programming assignments. I don`t know if it is only happening to me but sometimes, particularly when deadline is approaching, i find myself in a harsh situation. I cannot find my mistake in the code or come up with a another great idea. Then boredom comes in and the problem begins to seem unsolvable. I know there are more-than-great professional coders here. I would like to learn their ideas to cope with this situation. Is it better to focus on something else for a while and try again or try harder and harder and look for the solution on the net etc...

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  • Hi, i have a c programming doubt? I want to know the difference between the two and where one is use

    - by aks
    Hi, i have a c programming doubt? I want to know the difference between the two and where one is useful over other? suppose i have a struct called employee as below: struct emp{ char first_name[10]; char last_name[10]; char key[10]; }; Now, i want to store the table of employee records, then which method should i use: struct emp e1[100]; // Or struct emp * e1[100]; I know the two are not same but would like to know a use case where second declaration would be of interest and more advantageous to use? Can someone clarify?

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  • An XEvent a Day (4 of 31) – Querying the Session Definition and Active Session DMV’s

    - by Jonathan Kehayias
    Yesterdays post, Managing Event Sessions , showed how to manage Event Sessions in Extended Events Sessions inside the Extended Events framework in SQL Server. In today's post, we’ll take a look at how to find information about the defined Event Sessions that already exist inside a SQL Server using the Session Definition DMV’s and how to find information about the Active Event Sessions that exist using the Active Session DMV’s. Session Definition DMV’s The Session Definition DMV’s provide information...(read more)

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  • SQLAuthority News – Reliving TechEd with Vinod Kumar at Bangalore User Groups

    - by pinaldave
    TechEd India 2012 was held in Bangalore last March 21 to 23, 2012. Just like every year, this event is bigger, grander and inspiring. Here is my blog post reviewing the event SQLAuthority News – #TechEdIn – TechEd India 2012 Memories and Photos. For me this is family event – I get to meet my friends who are dear as my family. I like to call User Groups as family too. Family shares life’s personal happiness and experience – the same way User Group shares professional experiences and quite often UG members become just like family member. When I learned that follower user group together building up a unique event I was pretty excited to learn who is going to be speaker for the event. BDotNet.in – Bangalore .NET Usergroup BITPro.in – Bangalore ITPro Usergroup It was indeed joy when I learned that presenter will be Vinod Kumar, who is integral part of user groups and hardcore SQL Server enthusiast. Vinod Kumar is going to present on following two sessions which are both focused on internals of the Windows and SQL Server. Understanding Windows with SysInternals Tools – This session will cover various tools from usage of Memory, x86 architecture, x64, WOW mode, Page faults, Virtual Memory mapping, OOM scenario, Perf Tool, PAL tool, Logman and more. Peeling the Onion: SQL Server Internals Demystified – This session will cover advanced disk formats, SQL Server 2012 security changes, memory changes, indirect checkPoint and more. I am very excited as this time I will get opportunity to sit in front rows (as I will be reaching there to get best possible position) and learn. I am looking forward to the event and I hope you will join us as well. Event Details: Date: Saturday, April 7, 2012 (10:30am until 1:30pm) Venue: Microsoft, Domlur, Bangalore. Event Details: https://www.facebook.com/events/139444029517882/ This session is FREE for all and everybody and anybody can walk in. Community Blog Posts Here are few of the blog post written by the community on this subject. Vinod Kumar on Reliving #TechEdIn at Blr UG Manas Dash on Reliving TechEd India 2012 with Vinod Kumar Sudeepta Ganguly on SysInternals n SQLInternals with Vinod Kumar Lohith Re Live TechEd India 2012 with Vinod Kumar  Reference: Pinal Dave (http://blog.sqlauthority.com) http://www.youtube.com/watch?v=oRw-p4mahLU Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology, Video

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  • Upcoming presentations by me at Windows Azure Events

    - by ScottGu
    I recently blogged about a big wave of improvements we recently released for Windows Azure.  I also delivered a keynote on June 7th that discussed and demoed the enhancements – you can watch a recorded version of it online. Over the next few weeks I’ll be doing several more speaking events about Windows Azure in North America and Europe.  Below are details on some of the upcoming the events and how you can sign-up to attend one in person: Scottsdale, Arizona on June 19th, 2012 Attend this FREE all-day event in Scottsdale, Arizona on Tuesday, June 19th to learn more about Windows Azure, ASP.NET, Web API and SignalR.  I’ll be doing a 2 hour presentation on Windows Azure, followed by Scott Hanselman on ASP.NET and Web API, and Brady Gaster on SignalR.  Learn more about the event and register to attend here. Cambridge, United Kingdom on June 21st, 2012 Attend this FREE two-hour event in Cambridge (UK) the evening of Thursday, June 21st.  I’ll be covering the new Windows Azure release – expects lots of demos and audience participation. Learn more about the event and register to attend here. London, United Kingdom on June 22nd, 2012 Attend the FREE all-day Microsoft Cloud Day conference in London (UK) on Friday, June 22nd to learn about Windows Azure and Windows 8.  I’ll be kicking off the event with a two hour keynote, and will be followed by some other fantastic speakers. Learn more about the conference and register to attend here. TechEd Europe in Amsterdam, Netherlands on June 26th, 2012 I’ll be at TechEd Europe this year where I’ll be presenting on Windows Azure.  I’ll be in the general session keynote and also have a foundation track session on Windows Azure on Tuesday, June 26th. Learn more about TechEd Europe and register to attend here. Amsterdam, Netherlands on June 26th, 2012 Not attending TechEd Europe but near Amsterdam and still want to see me talk?  The good news is that the leaders of the Windows Azure User Group NL have setup a FREE event during the evening of Tuesday, June 26th where I’ll be presenting along with Clemens Vasters. Learn more about the event and register to attend here. Dallas, Texas on July 10th, 2012 I’ll be in Dallas, Texas on Tuesday, July 10th and presenting at a FREE all day Microsoft Cloud Summit.  I’ll kick off the day with a keynote, which will be followed by a great set of additional Windows Azure talks as well as a “Grill the Gu” Q&A session with me over lunch. Learn more about the event and register to attend here. Additional Events I’ll be doing many more events and talks in the months ahead – I’ll blog details of additional conferences/events I’m doing as they are fixed. Hope to see some of you at the above ones! Scott

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  • Best practices for logging and tracing in .NET

    - by Levidad
    I've been reading a lot about tracing and logging, trying to find some golden rule for best practices in the matter, but there isn't any. People say that good programmers produce good tracing, but put it that way and it has to come from experience. I've also read similar questions in here and through the internet and they are not really the same thing I am asking or do not have a satisfying answer, maybe because the questions lack some detail. So, folks say that tracing should sort of replicate the experience of debugging the application in cases where you can't attach a debugger. It should provide enough context so that you can see which path is taken at each control point in the application. Going deeper, you can even distinguish between tracing and event logging, in that "event logging is different from tracing in that it captures major states rather than detailed flow of control". Now, say I want to do my tracing and logging using only the standard .NET classes, those in the System.Diagnostics namespace. I figured that the TraceSource class is better for the job than the static Trace class, because I want to differentiate among the trace levels and using the TraceSource class I can pass in a parameter informing the event type, while using the Trace class I must use Trace.WriteLineIf and then verify things like SourceSwitch.TraceInformation and SourceSwitch.TraceErrors, and it doesn't even have properties like TraceVerbose or TraceStart. With all that in mind, would you consider a good practice to do as follows: Trace a "Start" event when begining a method, which should represent a single logical operation or a pipeline, along with a string representation of the parameter values passed in to the method. Trace an "Information" event when inserting an item into the database. Trace an "Information" event when taking one path or another in an important if/else statement. Trace a "Critical" or "Error" in a catch block depending on weather this is a recoverable error. Trace a "Stop" event when finishing the execution of the method. And also, please clarify when best to trace Verbose and Warning event types. If you have examples of code with nice trace/logging and are willing to share, that would be excelent. Note: I've found some good information here, but still not what I am looking for: http://msdn.microsoft.com/en-us/magazine/ff714589.aspx Thanks in advance!

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  • Open GL polygons not displaying

    - by Darestium
    I have tried to follow nehe's opengl tutorial lesson 2. I use sfml for my window creation. The problem I have is that both the triangle and the quad don't show up on the screen: #include <SFML/System.hpp> #include <SFML/Window.hpp> #include <iostream> void processEvents(sf::Window *app); void processInput(sf::Window *app, const sf::Input &input); void renderCube(sf::Window *app, sf::Clock *clock); void renderGlScene(sf::Window *app); void init(); int main() { sf::Window app(sf::VideoMode(800, 600, 32), "Nehe Lesson 2"); app.UseVerticalSync(false); init(); while (app.IsOpened()) { processEvents(&app); renderGlScene(&app); app.Display(); } return EXIT_SUCCESS; } void init() { glClearDepth(1.f); glClearColor(0.f, 0.f, 0.f, 0.f); // Enable z-buffer and read and write glEnable(GL_DEPTH_TEST); glDepthMask(GL_TRUE); // Setup a perpective projection glMatrixMode(GL_MODELVIEW); glLoadIdentity(); gluPerspective(45.f, 1.f, 1.f, 500.f); glShadeModel(GL_SMOOTH); } void processEvents(sf::Window *app) { sf::Event event; while (app->GetEvent(event)) { if (event.Type == sf::Event::Closed) { app->Close(); } if (event.Type == sf::Event::KeyPressed && event.Key.Code == sf::Key::Escape) { app->Close(); } } } void renderGlScene(sf::Window *app) { app->SetActive(); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear the screen and the depth buffer glLoadIdentity(); // Reset the view glTranslatef(-1.5f, 0.0f, -6.0f); // Move Left 1.5 units and into the screen 6.0 glBegin(GL_TRIANGLES); glVertex3f( 0.0f, 1.0f, 0.0f); // Top glVertex3f(-1.0,-1.0f, 0.0f); // Bottom Left glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right glEnd(); glTranslatef(3.0f, 0.0f, 0.0f); glBegin(GL_QUADS); // Draw a quad glVertex3f(-1.0f, 1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 0.0f); glVertex3f( 1.0f,-1.0f, 0.0f); glVertex3f(-1.0f,-1.0f, 0.0f); glEnd(); } I would greatly appreciate it if someone could help me resolve my issue.

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  • Building services with .Net Part 1

    - by Allan Rwakatungu
    On the 26th of May 2010 , I made a presentation to the .NET user group meeting (thanks to Malisa Ncube for organizing this event every month … ). If you missed my presentation , we talked about why we should all be building services … better still using the .NET framework. This blog post is an introduction to services , why you would want to build services and how you can build services using the .NET framework. What is a service? OASIS defines service as "a mechanism to enable access to one or more capabilities, where the access is provided using a prescribed interface and is exercised consistent with constraints and policies as specified by the service description." [1]. If the above definition sounds to academic , you can also define a service as loosely coupled units of functionality that have no calls to each other embedded in the. Instead of services embedding calls to each other in their service code they use defined protocols that describe how services pass and parse messages. This is a good way to think about services if you’re from an objected oriented background. While in object oriented programming functions make calls to each other, in service oriented programming, functions pass messages between each other. Why would you want to use services? 1. If your enterprise architecture looks like this   Services are the building blocks for SOA . With SOA you can move away from the sphaggetti infrastructure that is common in most enterprises. The complexity or lack of visibility of the integration points in your enterprises makes it difficult and costly to implement new initiatives and changes into the business - and even impossible in some cases - as it is not possible to identify the impact a change in one system might have to other systems. With services you can move to an architecture like this Your building blocks from Spaghetti infrastructure to something that is more well-defined and manageable to achieve cost efficiency and not least business agility - enabling you to react to changes in the market with speed and achieve operational efficiency and control are services. 2. If you want to become the Gates or Zuckerburger. Have you heard about Web 2.0 ? Mashups? Software as a service (SAAS) ? Cloud computing ?   They all offer you the opportunity to have scalable but low cost business models and they built using services.  Some of my favorite companies that leverage services for their business models include  https://www.salesforce.com/ (cloud CRM) http://www. twitter.com (more people use twitter clients built by 3rd parties than their official clients) http://www.kayak.com/ (compares data from other travel sites to give information to users in one location) Services with the .NET framework      If you are a .NET developer and you want to develop services, Windows Communication Framework (WCF) is the tool for you. WCF is Microsoft’s unified programming model (service model) for building service oriented applications. ( Before .NET 3.0 you had several models for programming services in .NET including .NET remoting, Web services (ASMX), COM +, Microsoft Messaging queuing (MSMQ) etc, after .NET 3.0 the programming model was unified into one i.e. WCF ). Windows Communication Framework (WCF) provides you 1. An Software Development Kit (SDK) for creating SOA applications 2. A runtime for running services on the Windows platform Why should you use Windows Communication Foundation if you’re programming services?   1. It supports interoperable and open standards e.g. WS* protocols for programming SOAP services 2. It has a unified programming model. Whether you use TCP or Http or Pipes or transmitting using Messaging Queues, programmers need to learn just one way to program. Previously you had .NET remoting, MSMQ, Web services, COM+ and they were all done differently 3. Productive programming model You don’t have to worry about all the plumbing involved to write services. You have a rich declarative programming model to add stuff like logging, transactions, and reliable messages in-built in the Windows Communication Framework. Understanding services in WCF The basic principles of WCF are as easy as ABC A – Address This is where the service is located B- Binding This describes how you communicate with the service e.g. Use TCP, HTTP or both. How to exchange security information with the service etc. C – Contract This defines what the service can do. E.g. Pay water bill, Make a phone call A - Addresses In WCF, an address is a combination of transport, server name, port and path Example addresses may include http://localhost:8001 net.tcp://localhost:8002/MyService net.pipe://localhost/MyPipe net.msmq://localhost/private/MyService net.msmq://localhost/MyService B- Binding   There are numerous ways to communicate with services , different ways that a message can be formatted/sent/secured, that allows you to tailor your service for the compatibility/performance you require for your solution. Transport You can use HTTP TCP MSMQ , Named pipes, Your own custom transport etc Message You  can send a plain text binary, Message Transmission Optimization Mechanism (MTOM) message Communication security No security Transport security Message security Authenticating and authorizing callers etc Behaviour You service can support Transactions Be reliable Use queues Support ajax etc C - Contract You define what your service can do using Service contracts :- Define operations that your service can do, communications and behaviours Data contracts :- Define the messages that are passed from and into your service and how they are formatted Fault contracts :- Defines errors types in your service   As an example, suppose your service service shows money. You define your service contract using a interface [ServiceContract] public interface IShowMeTheMoney {   [OperationContract]    Money Show(); } You define the data contract by annotating a class it with the Data Contract attribute and fields you want to pass in the message as Data Members. (Note:- In the latest versions of WCF you dont have to use attributes if you passing all the objects properties in the message) [DataContract] public Money {   [DataMember]   public string Currency { get; set; }   [DataMember]   public Decimal Amount { get; set; }   public string Comment { get; set; } } Features of Windows Communication Foundation Windows Communication Foundation is not only simple but feature rich , offering you several options to tweak your service to fit your business requirements. Some of the features of WCF include 1. Workflow services You can combine WCF with Windows WorkFlow Foundation (WWF) to write workflow type services 2. Control how your data (messages) are transferred and serialized e.g. you can serialize your business objects as XML or binary 3. control over session management , instance creation and concurrency management without writing code if you like 4. Queues and reliable sessions. You can store messages from the sending client and later forward them to the receiving application. You can also guarantee that messages will arrive at their destincation. 5.Transactions:  You can have different services participate in a transaction operations that can be rolled back if needed 6. Security. WCF has rich features for authorization and authentication  as well as keep audit trails 7. Web programming model. WCF allows developers to expose services as non SOAP endpoints 8. Inbuilt features that you can use to write JSON and services that support AJAX applications And lots more In my next blog I will show you how you can use WCF features to write a real world business service.               Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 ]] /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Is it possible to call Javascript's onsubmit event programatically on a form?

    - by hoyhoy
    In Ruby on Rails, I'm attempting to update the innerHTML of a div tag using the form_remote_tag helper. This update happens whenever an associated select tag receives an onchange event. The problem is, <select onchange="this.form.submit();">; doesn't work. Nor does document.forms[0].submit(). The only way to get the onsubmit code generated in the form_remote_tag to execute is to create a hidden submit button, and invoke the click method on the button from the select tag. Here's a working ERb partial example. <% form_remote_tag :url => product_path, :update => 'content', :method => 'get' do -%> <% content_tag :div, :id => 'content' do -%> <%= select_tag :update, options_for_select([["foo", 1], ["bar", 2]]), :onchange => "this.form.commit.click" %> <%= submit_tag 'submit_button', :style => "display: none" %> <% end %> <% end %> What I want to do is something like this, but it doesn't work. <% form_remote_tag :url => product_path, :update => 'content', :method => 'get' do -%> <% content_tag :div, :id => 'content' do -%> # the following line does not work <%= select_tag :update, options_for_select([["foo", 1], ["bar", 2]]), :onchange => "this.form.onsubmit()" %> <% end %> <% end %> So, is there any way to remove the invisible submit button for this use case? There seems to be some confusion. So, let me explain. The basic problem is that submit() doesn't call the onsubmit() code rendered into the form. The actual HTML form that Rails renders from this ERb looks like this: <form action="/products/1" method="post" onsubmit="new Ajax.Updater('content', '/products/1', {asynchronous:true, evalScripts:true, method:'get', parameters:Form.serialize(this)}); return false;"> <div style="margin:0;padding:0"> <input name="authenticity_token" type="hidden" value="4eacf78eb87e9262a0b631a8a6e417e9a5957cab" /> </div> <div id="content"> <select id="update" name="update" onchange="this.form.commit.click"> <option value="1">foo</option> <option value="2">bar</option> </select> <input name="commit" style="display: none" type="submit" value="submit_button" /> </div> </form> I want to axe the invisible submit button, but using a straight form.submit appears to not work. So, I need some way to call the form's onsubmit event code. Update: Orion Edwards solution would work if there wasn't a return(false); generated by Rails. I'm not sure which is worse though, sending a phantom click to an invisible submit button or calling eval on the getAttribute('onsubmit') call after removing the return call with a javascript string replacement!

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  • Metro: Creating a Master/Detail View with a WinJS ListView Control

    - by Stephen.Walther
    The goal of this blog entry is to explain how you can create a simple master/detail view by using the WinJS ListView and Template controls. In particular, I explain how you can use a ListView control to display a list of movies and how you can use a Template control to display the details of the selected movie. Creating a master/detail view requires completing the following four steps: Create the data source – The data source contains the list of movies. Declare the ListView control – The ListView control displays the entire list of movies. It is the master part of the master/detail view. Declare the Details Template control – The Details Template control displays the details for the selected movie. It is the details part of the master/detail view. Handle the selectionchanged event – You handle the selectionchanged event to display the details for a movie when a new movie is selected. Creating the Data Source There is nothing special about our data source. We initialize a WinJS.Binding.List object to represent a list of movies: (function () { "use strict"; var movies = new WinJS.Binding.List([ { title: "Star Wars", director: "Lucas"}, { title: "Shrek", director: "Adamson" }, { title: "Star Trek", director: "Abrams" }, { title: "Spiderman", director: "Raimi" }, { title: "Memento", director: "Nolan" }, { title: "Minority Report", director: "Spielberg" } ]); // Expose the data source WinJS.Namespace.define("ListViewDemos", { movies: movies }); })(); The data source is exposed to the rest of our application with the name ListViewDemos.movies. Declaring the ListView Control The ListView control is declared with the following markup: <div id="movieList" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.movies.dataSource, itemTemplate: select('#masterItemTemplate'), tapBehavior: 'directSelect', selectionMode: 'single', layout: { type: WinJS.UI.ListLayout } }"> </div> The data-win-options attribute is used to set the following properties of the ListView control: itemDataSource – The ListView is bound to the list of movies which we created in the previous section. Notice that the ListView is bound to ListViewDemos.movies.dataSource and not just ListViewDemos.movies. itemTemplate – The item template contains the template used for rendering each item in the ListView. The markup for this template is included below. tabBehavior – This enumeration determines what happens when you tap or click on an item in the ListView. The possible values are directSelect, toggleSelect, invokeOnly, none. Because we want to handle the selectionchanged event, we set tapBehavior to the value directSelect. selectionMode – This enumeration determines whether you can select multiple items or only a single item. The possible values are none, single, multi. In the code above, this property is set to the value single. layout – You can use ListLayout or GridLayout with a ListView. If you want to display a vertical ListView, then you should select ListLayout. You must associate a ListView with an item template if you want to render anything interesting. The ListView above is associated with an item template named #masterItemTemplate. Here’s the markup for the masterItemTemplate: <div id="masterItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="movie"> <span data-win-bind="innerText:title"></span> </div> </div> This template simply renders the title of each movie. Declaring the Details Template Control The details part of the master/detail view is created with the help of a Template control. Here’s the markup used to declare the Details Template control: <div id="detailsTemplate" data-win-control="WinJS.Binding.Template"> <div> <div> Title: <span data-win-bind="innerText:title"></span> </div> <div> Director: <span data-win-bind="innerText:director"></span> </div> </div> </div> The Details Template control displays the movie title and director.   Handling the selectionchanged Event The ListView control can raise two types of events: the iteminvoked and selectionchanged events. The iteminvoked event is raised when you click on a ListView item. The selectionchanged event is raised when one or more ListView items are selected. When you set the tapBehavior property of the ListView control to the value “directSelect” then tapping or clicking a list item raised both the iteminvoked and selectionchanged event. Tapping a list item causes the item to be selected and the item appears with a checkmark. In our code, we handle the selectionchanged event to update the movie details Template when you select a new movie. Here’s the code from the default.js file used to handle the selectionchanged event: var movieList = document.getElementById("movieList"); var detailsTemplate = document.getElementById("detailsTemplate"); var movieDetails = document.getElementById("movieDetails"); // Setup selectionchanged handler movieList.winControl.addEventListener("selectionchanged", function (evt) { if (movieList.winControl.selection.count() > 0) { movieList.winControl.selection.getItems().then(function (items) { // Clear the template container movieDetails.innerHTML = ""; // Render the template detailsTemplate.winControl.render(items[0].data, movieDetails); }); } }); The code above sets up an event handler (listener) for the selectionchanged event. The event handler first verifies that an item has been selected in the ListView (selection.count() > 0). Next, the details for the movie are rendered using the movie details Template (we created this Template in the previous section). The Complete Code For the sake of completeness, I’ve included the complete code for the master/detail view below. I’ve included both the default.html, default.js, and movies.js files. Here is the final code for the default.html file: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>ListViewMasterDetail</title> <!-- WinJS references --> <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> <!-- ListViewMasterDetail references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/movies.js"></script> <style type="text/css"> body { font-size: xx-large; } .movie { padding: 5px; } #masterDetail { display: -ms-box; } #movieList { width: 300px; margin: 20px; } #movieDetails { margin: 20px; } </style> </head> <body> <!-- Templates --> <div id="masterItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="movie"> <span data-win-bind="innerText:title"></span> </div> </div> <div id="detailsTemplate" data-win-control="WinJS.Binding.Template"> <div> <div> Title: <span data-win-bind="innerText:title"></span> </div> <div> Director: <span data-win-bind="innerText:director"></span> </div> </div> </div> <!-- Master/Detail --> <div id="masterDetail"> <!-- Master --> <div id="movieList" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.movies.dataSource, itemTemplate: select('#masterItemTemplate'), tapBehavior: 'directSelect', selectionMode: 'single', layout: { type: WinJS.UI.ListLayout } }"> </div> <!-- Detail --> <div id="movieDetails"></div> </div> </body> </html> Here is the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll(); var movieList = document.getElementById("movieList"); var detailsTemplate = document.getElementById("detailsTemplate"); var movieDetails = document.getElementById("movieDetails"); // Setup selectionchanged handler movieList.winControl.addEventListener("selectionchanged", function (evt) { if (movieList.winControl.selection.count() > 0) { movieList.winControl.selection.getItems().then(function (items) { // Clear the template container movieDetails.innerHTML = ""; // Render the template detailsTemplate.winControl.render(items[0].data, movieDetails); }); } }); } }; app.start(); })();   Here is the movies.js file: (function () { "use strict"; var movies = new WinJS.Binding.List([ { title: "Star Wars", director: "Lucas"}, { title: "Shrek", director: "Adamson" }, { title: "Star Trek", director: "Abrams" }, { title: "Spiderman", director: "Raimi" }, { title: "Memento", director: "Nolan" }, { title: "Minority Report", director: "Spielberg" } ]); // Expose the data source WinJS.Namespace.define("ListViewDemos", { movies: movies }); })();   Summary The purpose of this blog entry was to describe how to create a simple master/detail view by taking advantage of the WinJS ListView control. We handled the selectionchanged event of the ListView control to display movie details when you select a movie in the ListView.

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  • Metro: Creating a Master/Detail View with a WinJS ListView Control

    - by Stephen.Walther
    The goal of this blog entry is to explain how you can create a simple master/detail view by using the WinJS ListView and Template controls. In particular, I explain how you can use a ListView control to display a list of movies and how you can use a Template control to display the details of the selected movie. Creating a master/detail view requires completing the following four steps: Create the data source – The data source contains the list of movies. Declare the ListView control – The ListView control displays the entire list of movies. It is the master part of the master/detail view. Declare the Details Template control – The Details Template control displays the details for the selected movie. It is the details part of the master/detail view. Handle the selectionchanged event – You handle the selectionchanged event to display the details for a movie when a new movie is selected. Creating the Data Source There is nothing special about our data source. We initialize a WinJS.Binding.List object to represent a list of movies: (function () { "use strict"; var movies = new WinJS.Binding.List([ { title: "Star Wars", director: "Lucas"}, { title: "Shrek", director: "Adamson" }, { title: "Star Trek", director: "Abrams" }, { title: "Spiderman", director: "Raimi" }, { title: "Memento", director: "Nolan" }, { title: "Minority Report", director: "Spielberg" } ]); // Expose the data source WinJS.Namespace.define("ListViewDemos", { movies: movies }); })(); The data source is exposed to the rest of our application with the name ListViewDemos.movies. Declaring the ListView Control The ListView control is declared with the following markup: <div id="movieList" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.movies.dataSource, itemTemplate: select('#masterItemTemplate'), tapBehavior: 'directSelect', selectionMode: 'single', layout: { type: WinJS.UI.ListLayout } }"> </div> The data-win-options attribute is used to set the following properties of the ListView control: itemDataSource – The ListView is bound to the list of movies which we created in the previous section. Notice that the ListView is bound to ListViewDemos.movies.dataSource and not just ListViewDemos.movies. itemTemplate – The item template contains the template used for rendering each item in the ListView. The markup for this template is included below. tabBehavior – This enumeration determines what happens when you tap or click on an item in the ListView. The possible values are directSelect, toggleSelect, invokeOnly, none. Because we want to handle the selectionchanged event, we set tapBehavior to the value directSelect. selectionMode – This enumeration determines whether you can select multiple items or only a single item. The possible values are none, single, multi. In the code above, this property is set to the value single. layout – You can use ListLayout or GridLayout with a ListView. If you want to display a vertical ListView, then you should select ListLayout. You must associate a ListView with an item template if you want to render anything interesting. The ListView above is associated with an item template named #masterItemTemplate. Here’s the markup for the masterItemTemplate: <div id="masterItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="movie"> <span data-win-bind="innerText:title"></span> </div> </div> This template simply renders the title of each movie. Declaring the Details Template Control The details part of the master/detail view is created with the help of a Template control. Here’s the markup used to declare the Details Template control: <div id="detailsTemplate" data-win-control="WinJS.Binding.Template"> <div> <div> Title: <span data-win-bind="innerText:title"></span> </div> <div> Director: <span data-win-bind="innerText:director"></span> </div> </div> </div> The Details Template control displays the movie title and director.   Handling the selectionchanged Event The ListView control can raise two types of events: the iteminvoked and selectionchanged events. The iteminvoked event is raised when you click on a ListView item. The selectionchanged event is raised when one or more ListView items are selected. When you set the tapBehavior property of the ListView control to the value “directSelect” then tapping or clicking a list item raised both the iteminvoked and selectionchanged event. Tapping a list item causes the item to be selected and the item appears with a checkmark. In our code, we handle the selectionchanged event to update the movie details Template when you select a new movie. Here’s the code from the default.js file used to handle the selectionchanged event: var movieList = document.getElementById("movieList"); var detailsTemplate = document.getElementById("detailsTemplate"); var movieDetails = document.getElementById("movieDetails"); // Setup selectionchanged handler movieList.winControl.addEventListener("selectionchanged", function (evt) { if (movieList.winControl.selection.count() > 0) { movieList.winControl.selection.getItems().then(function (items) { // Clear the template container movieDetails.innerHTML = ""; // Render the template detailsTemplate.winControl.render(items[0].data, movieDetails); }); } }); The code above sets up an event handler (listener) for the selectionchanged event. The event handler first verifies that an item has been selected in the ListView (selection.count() > 0). Next, the details for the movie are rendered using the movie details Template (we created this Template in the previous section). The Complete Code For the sake of completeness, I’ve included the complete code for the master/detail view below. I’ve included both the default.html, default.js, and movies.js files. Here is the final code for the default.html file: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>ListViewMasterDetail</title> <!-- WinJS references --> <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> <!-- ListViewMasterDetail references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/movies.js"></script> <style type="text/css"> body { font-size: xx-large; } .movie { padding: 5px; } #masterDetail { display: -ms-box; } #movieList { width: 300px; margin: 20px; } #movieDetails { margin: 20px; } </style> </head> <body> <!-- Templates --> <div id="masterItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="movie"> <span data-win-bind="innerText:title"></span> </div> </div> <div id="detailsTemplate" data-win-control="WinJS.Binding.Template"> <div> <div> Title: <span data-win-bind="innerText:title"></span> </div> <div> Director: <span data-win-bind="innerText:director"></span> </div> </div> </div> <!-- Master/Detail --> <div id="masterDetail"> <!-- Master --> <div id="movieList" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.movies.dataSource, itemTemplate: select('#masterItemTemplate'), tapBehavior: 'directSelect', selectionMode: 'single', layout: { type: WinJS.UI.ListLayout } }"> </div> <!-- Detail --> <div id="movieDetails"></div> </div> </body> </html> Here is the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll(); var movieList = document.getElementById("movieList"); var detailsTemplate = document.getElementById("detailsTemplate"); var movieDetails = document.getElementById("movieDetails"); // Setup selectionchanged handler movieList.winControl.addEventListener("selectionchanged", function (evt) { if (movieList.winControl.selection.count() > 0) { movieList.winControl.selection.getItems().then(function (items) { // Clear the template container movieDetails.innerHTML = ""; // Render the template detailsTemplate.winControl.render(items[0].data, movieDetails); }); } }); } }; app.start(); })();   Here is the movies.js file: (function () { "use strict"; var movies = new WinJS.Binding.List([ { title: "Star Wars", director: "Lucas"}, { title: "Shrek", director: "Adamson" }, { title: "Star Trek", director: "Abrams" }, { title: "Spiderman", director: "Raimi" }, { title: "Memento", director: "Nolan" }, { title: "Minority Report", director: "Spielberg" } ]); // Expose the data source WinJS.Namespace.define("ListViewDemos", { movies: movies }); })();   Summary The purpose of this blog entry was to describe how to create a simple master/detail view by taking advantage of the WinJS ListView control. We handled the selectionchanged event of the ListView control to display movie details when you select a movie in the ListView.

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  • A WPF Image Button

    - by psheriff
    Instead of a normal button with words, sometimes you want a button that is just graphical. Yes, you can put an Image control in the Content of a normal Button control, but you still have the button outline, and trying to change the style can be rather difficult. Instead I like creating a user control that simulates a button, but just accepts an image. Figure 1 shows an example of three of these custom user controls to represent minimize, maximize and close buttons for a borderless window. Notice the highlighted image button has a gray rectangle around it. You will learn how to highlight using the VisualStateManager in this blog post.Figure 1: Creating a custom user control for things like image buttons gives you complete control over the look and feel.I would suggest you read my previous blog post on creating a custom Button user control as that is a good primer for what I am going to expand upon in this blog post. You can find this blog post at http://weblogs.asp.net/psheriff/archive/2012/08/10/create-your-own-wpf-button-user-controls.aspx.The User ControlThe XAML for this image button user control contains just a few controls, plus a Visual State Manager. The basic outline of the user control is shown below:<Border Grid.Row="0"        Name="borMain"        Style="{StaticResource pdsaButtonImageBorderStyle}"        MouseEnter="borMain_MouseEnter"        MouseLeave="borMain_MouseLeave"        MouseLeftButtonDown="borMain_MouseLeftButtonDown">  <VisualStateManager.VisualStateGroups>  ... MORE XAML HERE ...  </VisualStateManager.VisualStateGroups>  <Image Style="{StaticResource pdsaButtonImageImageStyle}"         Visibility="{Binding Path=Visibility}"         Source="{Binding Path=ImageUri}"         ToolTip="{Binding Path=ToolTip}" /></Border>There is a Border control named borMain and a single Image control in this user control. That is all that is needed to display the buttons shown in Figure 1. The definition for this user control is in a DLL named PDSA.WPF. The Style definitions for both the Border and the Image controls are contained in a resource dictionary names PDSAButtonStyles.xaml. Using a resource dictionary allows you to create a few different resource dictionaries, each with a different theme for the buttons.The Visual State ManagerTo display the highlight around the button as your mouse moves over the control, you will need to add a Visual State Manager group. Two different states are needed; MouseEnter and MouseLeave. In the MouseEnter you create a ColorAnimation to modify the BorderBrush color of the Border control. You specify the color to animate as “DarkGray”. You set the duration to less than a second. The TargetName of this storyboard is the name of the Border control “borMain” and since we are specifying a single color, you need to set the TargetProperty to “BorderBrush.Color”. You do not need any storyboard for the MouseLeave state. Leaving this VisualState empty tells the Visual State Manager to put everything back the way it was before the MouseEnter event.<VisualStateManager.VisualStateGroups>  <VisualStateGroup Name="MouseStates">    <VisualState Name="MouseEnter">      <Storyboard>        <ColorAnimation             To="DarkGray"            Duration="0:0:00.1"            Storyboard.TargetName="borMain"            Storyboard.TargetProperty="BorderBrush.Color" />      </Storyboard>    </VisualState>    <VisualState Name="MouseLeave" />  </VisualStateGroup></VisualStateManager.VisualStateGroups>Writing the Mouse EventsTo trigger the Visual State Manager to run its storyboard in response to the specified event, you need to respond to the MouseEnter event on the Border control. In the code behind for this event call the GoToElementState() method of the VisualStateManager class exposed by the user control. To this method you will pass in the target element (“borMain”) and the state (“MouseEnter”). The VisualStateManager will then run the storyboard contained within the defined state in the XAML.private void borMain_MouseEnter(object sender,  MouseEventArgs e){  VisualStateManager.GoToElementState(borMain,    "MouseEnter", true);}You also need to respond to the MouseLeave event. In this event you call the VisualStateManager as well, but specify “MouseLeave” as the state to go to.private void borMain_MouseLeave(object sender, MouseEventArgs e){  VisualStateManager.GoToElementState(borMain,     "MouseLeave", true);}The Resource DictionaryBelow is the definition of the PDSAButtonStyles.xaml resource dictionary file contained in the PDSA.WPF DLL. This dictionary can be used as the default look and feel for any image button control you add to a window. <ResourceDictionary  ... >  <!-- ************************* -->  <!-- ** Image Button Styles ** -->  <!-- ************************* -->  <!-- Image/Text Button Border -->  <Style TargetType="Border"         x:Key="pdsaButtonImageBorderStyle">    <Setter Property="Margin"            Value="4" />    <Setter Property="Padding"            Value="2" />    <Setter Property="BorderBrush"            Value="Transparent" />    <Setter Property="BorderThickness"            Value="1" />    <Setter Property="VerticalAlignment"            Value="Top" />    <Setter Property="HorizontalAlignment"            Value="Left" />    <Setter Property="Background"            Value="Transparent" />  </Style>  <!-- Image Button -->  <Style TargetType="Image"         x:Key="pdsaButtonImageImageStyle">    <Setter Property="Width"            Value="40" />    <Setter Property="Margin"            Value="6" />    <Setter Property="VerticalAlignment"            Value="Top" />    <Setter Property="HorizontalAlignment"            Value="Left" />  </Style></ResourceDictionary>Using the Button ControlOnce you make a reference to the PDSA.WPF DLL from your WPF application you will see the “PDSAucButtonImage” control appear in your Toolbox. Drag and drop the button onto a Window or User Control in your application. I have not referenced the PDSAButtonStyles.xaml file within the control itself so you do need to add a reference to this resource dictionary somewhere in your application such as in the App.xaml.<Application.Resources>  <ResourceDictionary>    <ResourceDictionary.MergedDictionaries>      <ResourceDictionary         Source="/PDSA.WPF;component/PDSAButtonStyles.xaml" />    </ResourceDictionary.MergedDictionaries>  </ResourceDictionary></Application.Resources>This will give your buttons a default look and feel unless you override that dictionary on a specific Window or User Control or on an individual button. After you have given a global style to your application and you drag your image button onto a window, the following will appear in your XAML window.<my:PDSAucButtonImage ... />There will be some other attributes set on the above XAML, but you simply need to set the x:Name, the ToolTip and ImageUri properties. You will also want to respond to the Click event procedure in order to associate an action with clicking on this button. In the sample code you download for this blog post you will find the declaration of the Minimize button to be the following:<my:PDSAucButtonImage       x:Name="btnMinimize"       Click="btnMinimize_Click"       ToolTip="Minimize Application"       ImageUri="/PDSA.WPF;component/Images/Minus.png" />The ImageUri property is a dependency property in the PDSAucButtonImage user control. The x:Name and the ToolTip we get for free. You have to create the Click event procedure yourself. This is also created in the PDSAucButtonImage user control as follows:private void borMain_MouseLeftButtonDown(object sender,  MouseButtonEventArgs e){  RaiseClick(e);}public delegate void ClickEventHandler(object sender,  RoutedEventArgs e);public event ClickEventHandler Click;protected void RaiseClick(RoutedEventArgs e){  if (null != Click)    Click(this, e);}Since a Border control does not have a Click event you will create one by using the MouseLeftButtonDown on the border to fire an event you create called “Click”.SummaryCreating your own image button control can be done in a variety of ways. In this blog post I showed you how to create a custom user control and simulate a button using a Border and Image control. With just a little bit of code to respond to the MouseLeftButtonDown event on the border you can raise your own Click event. Dependency properties, such as ImageUri, allow you to set attributes on your custom user control. Feel free to expand on this button by adding additional dependency properties, change the resource dictionary, and even the animation to make this button look and act like you want.NOTE: You can download the sample code for this article by visiting my website at http://www.pdsa.com/downloads. Select “Tips & Tricks”, then select “A WPF Image  Button” from the drop down list.

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  • MVVM Light V4 preview (BL0014) release notes

    - by Laurent Bugnion
    I just pushed to Codeplex an update to the MVVM Light source code. This is an early preview containing some of the features that I want to release later under the version 4. If you find these features useful for your project, please download the source code and build the assemblies. I will appreciate greatly any issue report. This version is labeled “V4.0.0.0/BL0014”. The “BL” string is an old habit that we used in my days at Siemens Building Technologies, called a “base level”. Somehow I like this way of incrementing the “base level” independently of any other consideration (such as alpha, beta, CTP, RTM etc) and continue to use it to tag my software versions. In Microsoft parlance, you could say that this is an early CTP of MVVM Light V4. Caveat The code is unit tested, but as we all know this does not mean that there are no bugs This code has not yet been used in production. Again, your help in testing this is greatly appreciated, so please report all bugs to me! What’s new? The following features have been implemented: Misc Various “maintenance work”. All WPF assemblies (that is .NET35 and .NET4) now allow partially trusted callers. It means that you can use them in am XBAP in partial trust mode. Testing Various test updates Added Windows Phone 7 unit tests Note: For Windows Phone 7, due to an issue in the unit test framework, not all tests can be executed. I had to isolate those tests for the moment. The error was reported to Microsoft. ViewModelBase The constructor is now public to allow serialization (especially useful on the phone to tombstone the state). ViewModelBase.MessengerInstance now returns Messenger.Default unless it is set explicitly. Previously, MessengerInstance was returning null, which was complicating the code. Two new ways to raise the PropertyChanged event have been added. See below for details. Messenger Updated the IMessenger interface with all public members from the Messenger class. Previously some members were missing. A new Unregister method is now available, allowing to unregister a recipient for a given token. RelayCommand RaiseCanExecuteChanged now acts the same in Windows Presentation Foundation than in Silverlight. In previous versions, I was relying on the CommandManager to raise the CanExecuteChanged event in WPF. However, it was found to be too unreliable, and a more direct way of raising the event was found preferable. See below for details. Raising the PropertyChanged event A very much requested update is now included: the ability to raise the PropertyChanged event in a viewmodel without using “magic strings”. Personally, I don’t see strings as a major issue, thanks to two features of the MVVM Light Toolkit: In the DEBUG configuration, every time that the RaisePropertyChanged method is called, the name of the property is checked against all existing properties of the viewmodel. Should the property name be misspelled (because of a typo or refactoring), an exception is thrown, notifying the developer that something is wrong. To avoid impacting the performance, this check is only made in DEBUG configuration, but that should be enough to warn the developers in case they miss a rename. The property name is defined as a public constant in the “mvvminpc” code snippet. This allows checking the property name from another class (for example if the PropertyChanged event is handled in the view). It also allows changing the property name in one place only. However, these two safeguards didn’t satisfy some of the users, who requested another way to raise the PropertyChanged event. In V4, you can now do the following: Using lambdas private int _myProperty; public int MyProperty { get { return _myProperty; } set { if (_myProperty == value) { return; } _myProperty = value; RaisePropertyChanged(() => MyProperty); } } This raises the property changed event using a lambda expression instead of the property name. Light reflection is used to get the name. This supports Intellisense and can easily be refactored. You can also broadcast a PropertyChangedMessage using the Messenger.Default instance with: private int _myProperty; public int MyProperty { get { return _myProperty; } set { if (_myProperty == value) { return; } var oldValue = _myProperty; _myProperty = value; RaisePropertyChanged(() => MyProperty, oldValue, value, true); } } Using no arguments When the RaisePropertyChanged method is called within a setter, you can also omit the property name altogether. This will fail if executed outside of the setter however. Also, to avoid confusion, there is no way to broadcast the PropertyChangedMessage using this syntax. private int _myProperty; public int MyProperty { get { return _myProperty; } set { if (_myProperty == value) { return; } _myProperty = value; RaisePropertyChanged(); } } The old way Of course the “old” way is still supported, without broadcast: public const string MyPropertyName = "MyProperty"; private int _myProperty; public int MyProperty { get { return _myProperty; } set { if (_myProperty == value) { return; } _myProperty = value; RaisePropertyChanged(MyPropertyName); } } And with broadcast: public const string MyPropertyName = "MyProperty"; private int _myProperty; public int MyProperty { get { return _myProperty; } set { if (_myProperty == value) { return; } var oldValue = _myProperty; _myProperty = value; RaisePropertyChanged(MyPropertyName, oldValue, value, true); } } Performance considerations It is notorious that using reflection takes more time than using a string constant to get the property name. However, after measuring for all platforms, I found the differences to be very small. I will measure more and submit the results to the community for evaluation, because some of the results are actually surprising (for example, using the Messenger to broadcast a PropertyChangedMessage does not significantly increase the time taken to raise the PropertyChanged event and update the bindings). For now, I submit this code to you, and would be delighted to hear about your own results. Raising the CanExecuteChanged event manually In WPF, until now, the CanExecuteChanged event for a RelayCommand was raised automatically. Or rather, it was attempted to be raised, using a feature that is only available in WPF called the CommandManager. This class monitors the UI and when something occurs, it queries the state of the CanExecute delegate for all the commands. However, this proved unreliable for the purpose of MVVM: Since very often the value of the CanExecute delegate changes according to non-UI events (for example something changing in the viewmodel or in the model), raising the CanExecuteChanged event manually is necessary. In Silverlight, the CommandManager does not exist, so we had to raise the event manually from the start. This proved more reliable, and I now changed the WPF implementation of the RaiseCanExecuteChanged method to be the exact same in WPF than in Silverlight. For instance, if a command must be enabled when a string property is set to a value other than null or empty string, you can do: public MainViewModel() { MyTestCommand = new RelayCommand( () => DoSomething(), () => !string.IsNullOrEmpty(MyProperty)); } public const string MyPropertyName = "MyProperty"; private string _myProperty = string.Empty; public string MyProperty { get { return _myProperty; } set { if (_myProperty == value) { return; } _myProperty = value; RaisePropertyChanged(MyPropertyName); MyTestCommand.RaiseCanExecuteChanged(); } } Logo update I made a minor change to the logo: Some people found the lack of the word “light” (as in MVVM Light Toolkit) confusing. I thought it was cool, because the feather suggests the idea of lightness, however I can see the point. So I added the word “light” to the logo. Things should be quite clear now. What’s next? This is only the first of a series of releases that will bring MVVM Light to V4. In the next weeks, I will continue to add some very requested features and correct some issues in the code. I will probably continue this fashion of releasing the changes to the public as source code through Codeplex. I would be very interested to hear what you think of that, and to get feedback about the changes. Cheers, Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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  • Anyone know about AppDynamics? Does Microsoft already have something similiar? Event viewer? Im confused

    - by punkouter
    We have a big collection of java (80%) and .Net (20%) apps.. And the people in charge want a way to monitor the applications somehow. So they told me they are interested in AppDynamics? I have spent a bit looking into it but I still don't get it. Can someone tell me what its about ? From my understanding it seems like you would someone inject the AppDynamics API in your code to tell about differnt events that occur? So sounds like Event Viewer ? I am on the .NET side of this and seems to me we can just write data to a log and report off of that data.. I don't get what the additional complexity of using'AppDynamics' does. Maybe it is overkill ??

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  • jquery livequery event triggered on EVERYTHING, not just selected element.

    - by phazei
    I am attempting to use livequery. I unfortunately am stuck using jquery 1.2.6. This is my code: $(document).ready(function() { $('a.sort').livequery('click', function(event) { alert('hello'); }); }); If I click ANYWHERE in the document, I get the alert 'hello'. What exactly is wrong there? Is it some bug with jQ1.2.6 and livequery 1.1.1? This same question was asked here but the question wasn't clear, and the answer didn't help.

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  • Using Xlib via JNA to move a window

    - by rob
    I'm using JNA to manipulate application windows on Linux by sending Xlib messages but can't seem to move a window. My original implementation executed wmctrl on the shell to move the windows and that successfully moved the windows. Unfortunately, there's a noticeable amount of overhead associated with calling shell programs from Java, so now I'm trying to make direct API calls using JNA. I'm using the X11 example available from the JNA website and can successfully do a few tricks, such as enumerating the window IDs and reading window properties, so I know JNA+Xlib is at least partially working. First I tried moving the windows directly using XMoveWindow() but the window manager was apparently blocking those calls. I ran across a thread that suggested I needed to send a client message using XSendMessage(), so I've done that below, but apparently XSendMessage() is failing because the window doesn't move and I get a return value of 0. I'm guessing I omitted something obvious, but can't quite figure it out. Any suggestions? Note that, for the purposes of this example, the main method has a window ID hard-coded. This is the window ID of the window I'm trying to move (obtained using wmctrl -l on the console). import com.sun.jna.NativeLong; import com.sun.jna.Pointer; import com.sun.jna.examples.unix.X11; import com.sun.jna.examples.unix.X11.Atom; import com.sun.jna.examples.unix.X11.AtomByReference; import com.sun.jna.examples.unix.X11.Display; import com.sun.jna.examples.unix.X11.Window; import com.sun.jna.examples.unix.X11.WindowByReference; import com.sun.jna.examples.unix.X11.XEvent; import com.sun.jna.examples.unix.X11.XTextProperty; import com.sun.jna.examples.unix.X11.XWindowAttributes; import com.sun.jna.ptr.IntByReference; import com.sun.jna.ptr.NativeLongByReference; import com.sun.jna.ptr.PointerByReference; private static final int FALSE = 0; /** C-style boolean "false" */ private static final int TRUE = 1; /** C-style boolean "true" */ public static void main(String[] args) { setWindowPos(new Window(0x01300007), 100, 100, 600, 400); // update the Window constructor with the appropriate ID given by wmctrl -l } public static boolean setWindowPos(Window window, int x, int y, int w, int h) { final X11 x11 = X11.INSTANCE; Display display = x11.XOpenDisplay(null); NativeLong mask = new NativeLong(X11.SubstructureRedirectMask | X11.SubstructureNotifyMask | X11.ResizeRedirectMask); XEvent event = new XEvent(); String msg = "_NET_MOVERESIZE_WINDOW"; //$NON-NLS-1$ long grflags = 0l; // use the default gravity of the window if (x != -1) grflags |= (1 << 8); if (y != -1) grflags |= (1 << 9); if (w != -1) grflags |= (1 << 10); if (h != -1) grflags |= (1 << 11); event.xclient.type = X11.ClientMessage; event.xclient.serial = new NativeLong(0l); event.xclient.send_event = TRUE; event.xclient.message_type = x11.XInternAtom(display, msg, false); event.xclient.window = window; event.xclient.format = 32; event.xclient.data.l[0] = new NativeLong(grflags); // gravity flags event.xclient.data.l[1] = new NativeLong(x); event.xclient.data.l[2] = new NativeLong(y); event.xclient.data.l[3] = new NativeLong(w); event.xclient.data.l[4] = new NativeLong(h); int status = x11.XSendEvent(display, x11.XDefaultRootWindow(display), FALSE, mask, event); x11.XFlush(display); // need to XFlush if we're not reading X events if (status == 0) { // 0 indicates XSendEvent failed logger.error("setWindowPos: XSendEvent failed (" + msg + ")"); //$NON-NLS-1$ return false; } return true; }

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  • Do WPF ComboBox SelectedIndex and SelectedValue have different behavior on SelectionChanged event?

    - by Junior Mayhé
    Hello guys I got this cbxJobPosition_SelectionChanged firing as expected. The problem is when a external method tries to set cbxJobPosition. cbxJobPosition is databinded with a list of objects of type JobPosition: JobPositionID: 1, JobPositionName: Manager JobPositionID: 2, JobPositionName: Employee JobPositionID: 3, JobPositionName: Third party Here's the XAML: <ComboBox Cursor="Hand" DataContext="{Binding}" ItemsSource="{Binding}" FontSize="13" Name="cbxJobPosition" SelectedValuePath="JobPositionID" DisplayMemberPath="JobPositionName" SelectedIndex="0" Width="233" Height="23" SelectionChanged="cbxJobPosition_SelectionChanged" /> On UserControl_Loaded method, it reads from database the list of jobs and try to set the specific job position "Third party": //calls cbxJobPosition_SelectionChanged and passes the correct SelectedValue within cbxJobPosition.SelectedIndex = 3; //calls cbxJobPosition_SelectionChanged and but won't pass the correct SelectedValue within cbxJobPosition.SelectedValue = "3"; As you can notice, when the processing is automatically redirected to cbxJobPosition_SelectionChanged, the SelectedValue attribute will have different values for each statement above when you're debugging within cbxJobPosition_SelectionChanged event. Does anyone know if this difference is expected, am I missing something or it could be a bug?

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  • How to bind Checked event for radio button in WPF?

    - by nullDev
    I am using the following markup in WPF: <StackPanel.Triggers> <EventTrigger RoutedEvent="RadioButton.Checked" SourceName="xmlRadioButton"> <EventTrigger.Actions> <BeginStoryboard Storyboard="{StaticResource ShowXmlPanel}"/> </EventTrigger.Actions> </EventTrigger> <EventTrigger RoutedEvent="RadioButton.Checked" SourceName="adiRadioButton"> <EventTrigger.Actions> <BeginStoryboard Storyboard="{StaticResource ShowAdiPanel}"/> </EventTrigger.Actions> </EventTrigger> </StackPanel.Triggers> Though this works fine when I run the code, I get the following error in the designer window of VS 2008: Value 'RadioButton.Checked' cannot be assigned to property 'RoutedEvent'. Invalid event name. Any idea why, and how can I fix this?

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  • Android: How to create an onclick event for a SimpleCursorAdapter?

    - by user117701
    I have this code: db=(new DatabaseHelper(this)).getWritableDatabase(); constantsCursor=db.rawQuery("SELECT _ID, title, subtitle, image "+ "FROM news ORDER BY title", null); ListAdapter adapter=new SimpleCursorAdapter(this, R.layout.row, constantsCursor, new String[] {"title", "subtitle", "image"}, new int[] {R.id.value, R.id.title, R.id.icon}); setListAdapter(adapter); registerForContextMenu(getListView()); Which displays a list of titles. I dont however for the life of me know how to create a click event so that i can call another view when i click an item from that list. Anyone?

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  • using Unity Android In a sub view and add style and actionbar

    - by aeroxr1
    I exported a simple animation from Unity3D (version 4.5) in android project. With eclipse I modified the manifest and added another activity. In this activity I put a button that it makes start the animation,and this is the result. The action bar appear in the main activity but it doesn't in the unity's activity :( This is the unity's activity's code : package com.rabidgremlin.tut.redcube; import android.app.NativeActivity; import android.content.res.Configuration; import android.graphics.PixelFormat; import android.os.Bundle; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.Window; import android.view.WindowManager; import com.unity3d.player.UnityPlayer; public class UnityPlayerNativeActivity extends NativeActivity { protected UnityPlayer mUnityPlayer; // don't change the name of this variable; referenced from native code // Setup activity layout @Override protected void onCreate (Bundle savedInstanceState) { //requestWindowFeature(Window.FEATURE_NO_TITLE); super.onCreate(savedInstanceState); getWindow().takeSurface(null); //setTheme(android.R.style.Theme_NoTitleBar_Fullscreen); getWindow().setFormat(PixelFormat.RGB_565); mUnityPlayer = new UnityPlayer(this); /*if (mUnityPlayer.getSettings ().getBoolean ("hide_status_bar", true)) getWindow ().setFlags (WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); */ setContentView(mUnityPlayer); mUnityPlayer.requestFocus(); } // Quit Unity @Override protected void onDestroy () { mUnityPlayer.quit(); super.onDestroy(); } // Pause Unity @Override protected void onPause() { super.onPause(); mUnityPlayer.pause(); } // eliminiamo questa onResume() e proviamo a modificare la onResume() // Resume Unity @Override protected void onResume() { super.onResume(); mUnityPlayer.resume(); } // inseriamo qualche modifica qui // This ensures the layout will be correct. @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); mUnityPlayer.configurationChanged(newConfig); } // Notify Unity of the focus change. @Override public void onWindowFocusChanged(boolean hasFocus) { super.onWindowFocusChanged(hasFocus); mUnityPlayer.windowFocusChanged(hasFocus); } // For some reason the multiple keyevent type is not supported by the ndk. // Force event injection by overriding dispatchKeyEvent(). @Override public boolean dispatchKeyEvent(KeyEvent event) { if (event.getAction() == KeyEvent.ACTION_MULTIPLE) return mUnityPlayer.injectEvent(event); return super.dispatchKeyEvent(event); } // Pass any events not handled by (unfocused) views straight to UnityPlayer @Override public boolean onKeyUp(int keyCode, KeyEvent event) { return mUnityPlayer.injectEvent(event); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { return mUnityPlayer.injectEvent(event); } @Override public boolean onTouchEvent(MotionEvent event) { return mUnityPlayer.injectEvent(event); } /*API12*/ public boolean onGenericMotionEvent(MotionEvent event) { return mUnityPlayer.injectEvent(event); } } How can I add the action bar and the style of the first activity to unity's animation activity ?

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