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• I need beginner help on loading an image (2D). I have an error

  - by Seth Taddiken

  I keep getting a "NullReferenceExeption was unhandled" with "Object reference not set to an instance of an object." written under it. I have all of the images (png) correct with names and added to references. protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); backGround = Content.Load("Cracked"); player1.playerBlock = Content.Load("square"); player2.playerBlock = Content.Load("square2"); }

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• rotating spheres

  - by Dave

  I want to continuously rotate 2 spheres, however the rotation does not seem to work. Here is my code: float angle = 0.0f; void light(){ glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glEnable(GL_LIGHT1); // Create light components GLfloat positionlight1[] = { 9.0, 5.0, 1.0, 0.0 }; GLfloat positionlight2[] = {0.2,2.5,1.3,0.0}; GLfloat light_ambient1[] = { 0.0, 0.0, 1.0, 1.0}; GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 }; glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient1); glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse); glLightfv(GL_LIGHT0, GL_POSITION, positionlight1); glLightfv(GL_LIGHT1, GL_POSITION, positionlight2); } void changeSize(int w, int h) { if (h==0) // Prevent A Divide By Zero By { h=1; // Making Height Equal One } glMatrixMode(GL_PROJECTION); // Select The Projection Matrix glLoadIdentity(); // Reset The Projection Matrix glViewport(0,0,w,h);// Reset The Current Viewport // Calculate The Aspect Ratio Of The Window gluPerspective(45.0f,(GLfloat)w/(GLfloat)h,0.1f,100.0f); glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix // Reset The Modelview Matrix } void renderScene(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); //set where to start the current object glTranslatef(0.0,1.2,-6); glRotatef(angle,0,1.2,-6); glutSolidSphere(1,50,50); glPopMatrix(); //end the current object transformations glPushMatrix(); //set where to start the current object glTranslatef(0.0,-2,-6); glRotatef(angle,0,-2,-6); glutSolidSphere(0.5,50,50); glPopMatrix(); //end the current object transformations angle=+0.1; glutSwapBuffers(); } int main(int argc, char **argv) { // init GLUT and create window glutInit(&argc, argv); glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); glutInitWindowPosition(100,100); glutInitWindowSize(500,500); glutCreateWindow("Hello World"); // register callbacks light(); glutDisplayFunc(renderScene); glutReshapeFunc(changeSize); glutIdleFunc(renderScene); // enter GLUT event processing loop glutMainLoop(); return 1; } Graphicstest::Graphicstest(void) { } In the renderscene where i draw,translate and rotate my 2 spheres. It does not seem to rotate the spheres continuously. What am i doing wrong?

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• Why has the accessor methods from the JavaBean specification become the standard for Java development?

  - by Dakotah North

  The JavaBeans Specification describes a JavaBean as A Java Bean is a reusable software component that can be manipulated visually in a builder tool Since the majority of the lines of code that are written seem to have nothing to do with being manipulated visually in a builder tool, why has the JavaBean specification been the "way" to write object oriented code? I would like to forgo the traditional getter/setter in favor of Fluent Interfaces all throughout the code, not just in builders but fear doing so since this is traditionally not the way way object oriented code is written in Java.

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• Question about design

  - by lukeluke

  Two fast questions about two design decisions: Suppose that you are checking collisions between game elements. When you find a collision between object 1 and object 2, do you play immediately a sound effect or do you insert it in a list and, in a later a stage, do you process all sound effects? Same question as above for user input. When the user presses key 'keypad left' do you insert the event in a queue and process it later or do you update character position immediately? Thx

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• Quickly Warning

  - by bradjones

  Every time I run my application I receive these warning errors can anyone tell me what is causing them? $ quickly run /usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py:391: Warning: g_object_set_property: construct property "type" for object `Window' can't be set after construction Gtk.Window.__init__(self, type=type, **kwds) /usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py:391: Warning: g_object_set_property: construct property "type" for object `AppWindow' can't be set after construction Gtk.Window.__init__(self, type=type, **kwds)

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• How to get a Read-Write Reference to Parent GameObject from a script component attached to it?

  - by onguarde

  I have a game object(object) with a script component(myscript) attached. I have a reference to myscript component through getComponent, and I want to change the transform of the gameObject the script is attached to. myscript.gameObject.transform = (new value); The above code gives me error, Property 'UnityEngine.GameObject.transform' is read only. Is there a way to get a read-write version?

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• Do first-class methods exist?

  - by gdhoward

  Okay, I know first-class functions are cool, closures even better, etc. But is there any language with first-class methods? In my mind, I see a first-class method as an "object" that has both a function pointer and a pointer to a specific instance of the class/object, but the implementation doesn't matter. I just want to know if there is any language that uses them. And as a bonus, how were they implemented?

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• BinarySerialization size not consist?! (2 replies)

  Hello all, I have met something pretty odd. I am running a serialization on an object and not always the size of the output stream is the same. I even created a test that I am running the serialization in a loop, and each time I am running I have different results sizes in some point in the loop. This happens when I am using a object that was filled in the server side, and I get them thru WCF work...

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• How would I detect if two 2D arrays of any shape collided?

  - by user2104648

  Say there's two or more moveable objects of any shape in 2D plane, each object has its own 2D boolean array to act as a bounds box which can range from 10 to 100 pixels, the program then reads each pixel from a image that represents it, and appropriatly changes the array to true(pixel has a alpha more then 1) or false(pixel has a alpha less than one). Each time one of these objects moves, what would be the best accurate way to test if they hit another object in Java using as few APIs/libraries as possible?

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• Requring static class setter to be called before constructor, bad design?

  - by roverred

  I have a class, say Foo, and every instance of Foo will need and contain the same List object, myList. Since every class instance will share the same List Object, I thought it would be good to make myList static and use a static function to set myList before the constructor is called. I was wondering if this was bad, because this requires the setter to be called before the constructor? If the person doesn't, the program will crash. Alternative way would be passing myList every time.

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• What's the difference between these design pattern books? [on hold]

  - by BSara

  I'm currently looking for a good reference/guide for design patterns and in my search I've found the following three books highly recommended: Design Patterns: Elements of Reusable Object-Oriented Software Pattern Hatching: Design Patterns Applied Design Patterns Explained: A New Perspective on Object-Oriented Design I can't decide which book (if any) to purchase. So, my question is this: What are the fundamental differences between these books?

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• Game programming and quantity of timers

  - by andresjb

  I've made a simple 2D game engine using C# and DirectX and it's fully functional for the demo I made to test it. I have a Timer object that uses QueryPerformanceCounter and I don't know what's the better choice: use only one timer in the game loop to update everything in the game, or an independent timer in every object that needs one. My worry is that when I try to implement threads, what will happen with timers? What happens with the sync?

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• Converting a PowerShell Script into a Module Part 2

  In this article the author explains how PSModuleInfo object for a module can be retrieved. Further, he shows how code can be injected into the module to manipulate the state of a module without having to reload it. He also explains how to directly set some metadata elements, like the module description, and some other PSModuleInfo object features.

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• BinarySerialization size not consist?! (2 replies)

  Hello all, I have met something pretty odd. I am running a serialization on an object and not always the size of the output stream is the same. I even created a test that I am running the serialization in a loop, and each time I am running I have different results sizes in some point in the loop. This happens when I am using a object that was filled in the server side, and I get them thru WCF work...

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• Inkscape: what are "line" objects?

  - by Peter Mortensen

  What is a "line" object in Inkscape? Drawing lines in Inkscape is by using the tool "Draw Bezier curves and straight lines (Shift+F6)". This creates objects of another type, "path". Using Inkscape: is there a way to convert an object of type "line" into an object of the more general type "path"? I have imported a drawing (mostly lines, rectangles and text) that has been through Adobe Illustrator: originally made in Inkscape, imported into Illustrator, edited, saved from Illustrator as SVG, imported into Inkscape. Sample from the imported SVG file: <path id="path5855" stroke="#000000" d=" M320.198,275.935" /> <line fill="none" stroke="#000000" x1="348.553" y1="45.097" x2="348.553" y2="185.346" id="line3368" /> Update 1: I have inspected the original XML (SVG) file from 2006 and it does not contain any "line" XML tags. Thus it must be a crime of Adobe Illustrator. When a line is selected in this imported SVG file the bottom panel displays: "Line in root. Click selection to toggle scale/rotation handles.". When a line is selected that was drawn in Inkscape the bottom panel displays: "Path (2 nodes) in Layer 1. Click selection to toggle scale/rotation handles." What is the difference between "line" and "path"? Is "line" some kind of read-only/non-editable object? A generic term like "line" is not easy to use in search, but I have now found the definitions for "line" and "path": SVG line: http://www.w3schools.com/svg/svg_line.asp SVG path: http://www.w3schools.com/svg/svg_path.asp Platform: Inkscape v0.46 (2008-03-10), Windows XP 64 bit, 8 GB RAM.

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• Problems with ipsec betwen Cisco ASA 5505 and Juniper ssg5

  - by Oskar Kjellin

  I am trying to set up an ipsec tunnel between our ASA 5505 and a Juniper ssg5. The tunnel is up and running, but I cannot get any data through it. The local network I am on is 172.16.1.0 and the remote is 192.168.70.0. But I cannot ping anything on their netowork. I receive a "Phase 2 OK" when I set up the ipsec. I think this is the part of the config that is applicable. It seems like the data is not routed through the tunnel, but I am not sure... object network our-network subnet 172.16.1.0 255.255.255.0 object network their-network subnet 192.168.70.0 255.255.255.0 access-list outside_cryptomap extended permit ip object our-network object their-network crypto ipsec ikev1 transform-set ESP-3DES-SHA esp-3des esp-sha-hmac crypto map outside_map 1 match address outside_cryptomap crypto map outside_map 1 set pfs crypto map outside_map 1 set peer THEIR_IP crypto map outside_map 1 set ikev1 phase1-mode aggressive crypto map outside_map 1 set ikev1 transform-set ESP-3DES-MD5 crypto map outside_map 1 set ikev2 pre-shared-key ***** crypto map outside_map 1 set reverse-route crypto map outside_map interface outside webvpn group-policy GroupPolicy_THEIR_IP internal group-policy GroupPolicy_THEIR_IP attributes vpn-filter value outside_cryptomap ipv6-vpn-filter none vpn-tunnel-protocol ikev1 tunnel-group THEIR_IP type ipsec-l2l tunnel-group THEIR_IP general-attributes default-group-policy GroupPolicy_THEIR_IP tunnel-group THEIR_IP ipsec-attributes ikev1 pre-shared-key ***** ikev2 remote-authentication pre-shared-key ***** ikev2 local-authentication pre-shared-key *****

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• Help me please with this error

  - by Brandon

  I setup IIS. I moved my folder with all the files to the IIS directory. Now when I go to http://localhost/thefolder I get: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B) Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B) Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)] Luxand.FSDK.ActivateLibrary(String LicenseKey) +0 FaceRecognition._Default.Page_Load(Object sender, EventArgs e) in D:\Project Details\Layne Projects\DotNet Project\FaceRecognition\FaceRecognition\Default.aspx.cs:60 System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +25 System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +42 System.Web.UI.Control.OnLoad(EventArgs e) +132 System.Web.UI.Control.LoadRecursive() +66 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2428

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• Windows Server task manager displays much higher memory use than sum of all processes' working set s

  - by Sleepless

  I have a 16 GB Windows Server 2008 x64 machine mostly running SQL Server 2008. The free memory as seen in Task Manager is very low (128 MB at the moment), i.e. about 15.7 GB are used. So far, so good. Now when I try to narrow down the process(es) using the most memory I get confused: None of the processes have more than 200MB Working Set Size as displayed in the 'Processes' tab of Task Manager. Well, maybe the Working Set Size isn't the relevant counter? To figure that out I used a PowerShell command [1] to sum up each individual property of the process object in sort of a brute force approach - surely one of them must add up to the 15.7 GB, right? Turns out none of them does, with the closest being VirtualMemorySize (around 12.7 GB) and PeakVirtualMemorySize (around 14.7 GB). WTF? To put it another way: Which of the numerous memory related process information is the "correct" one, i.e. counts towards the server's physical memory as displayed in the Task Manager's 'Performance' tab? Thank you all! [1] $erroractionpreference="silentlycontinue"; get-process | gm | where-object {$.membertype -eq "Property"} | foreach-object {$.name; (get-process | measure-object -sum $_.name ).sum / 1MB}

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• WPF TreeView MouseDown

  - by imekon

  I've got something like this in a TreeView: <DataTemplate x:Key="myTemplate"> <StackPanel MouseDown="OnItemMouseDown"> ... </StackPanel> </DataTemplate> Using this I get the mouse down events if I click on items in the stack panel. However... there seems to be another item behind the stack panel that is the TreeViewItem - it's very hard to hit, but not impossible, and that's when the problems start to occur. I had a go at handling PreviewMouseDown on TreeViewItem, however that seems to require e.Handled = false otherwise standard tree view behaviour stops working. Ok, Here's the source code... MainWindow.xaml <Window x:Class="WPFMultiSelectTree.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:WPFMultiSelectTree" Title="Multiple Selection Tree" Height="300" Width="300"> <Window.Resources> <!-- Declare the classes that convert bool to Visibility --> <local:VisibilityConverter x:Key="visibilityConverter"/> <local:VisibilityInverter x:Key="visibilityInverter"/> <!-- Set the style for any tree view item --> <Style TargetType="TreeViewItem"> <Style.Triggers> <DataTrigger Binding="{Binding Selected}" Value="True"> <Setter Property="Background" Value="DarkBlue"/> <Setter Property="Foreground" Value="White"/> </DataTrigger> </Style.Triggers> <EventSetter Event="PreviewMouseDown" Handler="OnTreePreviewMouseDown"/> </Style> <!-- Declare a hierarchical data template for the tree view items --> <HierarchicalDataTemplate x:Key="RecursiveTemplate" ItemsSource="{Binding Children}"> <StackPanel Margin="2" Orientation="Horizontal" MouseDown="OnTreeMouseDown"> <Ellipse Width="12" Height="12" Fill="Green"/> <TextBlock Margin="2" Text="{Binding Name}" Visibility="{Binding Editing, Converter={StaticResource visibilityInverter}}"/> <TextBox Margin="2" Text="{Binding Name}" KeyDown="OnTextBoxKeyDown" IsVisibleChanged="OnTextBoxIsVisibleChanged" Visibility="{Binding Editing, Converter={StaticResource visibilityConverter}}"/> <TextBlock Margin="2" Text="{Binding Index, StringFormat=({0})}"/> </StackPanel> </HierarchicalDataTemplate> <!-- Declare a simple template for a list box --> <DataTemplate x:Key="ListTemplate"> <TextBlock Text="{Binding Name}"/> </DataTemplate> </Window.Resources> <Grid> <!-- Declare the rows in this grid --> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition/> <RowDefinition Height="Auto"/> <RowDefinition/> </Grid.RowDefinitions> <!-- The first header --> <TextBlock Grid.Row="0" Margin="5" Background="PowderBlue">Multiple selection tree view</TextBlock> <!-- The tree view --> <TreeView Name="m_tree" Margin="2" Grid.Row="1" ItemsSource="{Binding Children}" ItemTemplate="{StaticResource RecursiveTemplate}"/> <!-- The second header --> <TextBlock Grid.Row="2" Margin="5" Background="PowderBlue">The currently selected items in the tree</TextBlock> <!-- The list box --> <ListBox Name="m_list" Margin="2" Grid.Row="3" ItemsSource="{Binding .}" ItemTemplate="{StaticResource ListTemplate}"/> </Grid> </Window> MainWindow.xaml.cs /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { private Container m_root; private Container m_first; private ObservableCollection<Container> m_selection; private string m_current; /// <summary> /// Constructor /// </summary> public MainWindow() { InitializeComponent(); m_selection = new ObservableCollection<Container>(); m_root = new Container("root"); for (int parents = 0; parents < 50; parents++) { Container parent = new Container(String.Format("parent{0}", parents + 1)); for (int children = 0; children < 1000; children++) { parent.Add(new Container(String.Format("child{0}", children + 1))); } m_root.Add(parent); } m_tree.DataContext = m_root; m_list.DataContext = m_selection; m_first = null; } /// <summary> /// Has the shift key been pressed? /// </summary> private bool ShiftPressed { get { return Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift); } } /// <summary> /// Has the control key been pressed? /// </summary> private bool CtrlPressed { get { return Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl); } } /// <summary> /// Clear down the selection list /// </summary> private void DeselectAndClear() { foreach(Container container in m_selection) { container.Selected = false; } m_selection.Clear(); } /// <summary> /// Add the container to the list (if not already present), /// mark as selected /// </summary> /// <param name="container"></param> private void AddToSelection(Container container) { if (container == null) { return; } foreach (Container child in m_selection) { if (child == container) { return; } } container.Selected = true; m_selection.Add(container); } /// <summary> /// Remove container from list, mark as not selected /// </summary> /// <param name="container"></param> private void RemoveFromSelection(Container container) { m_selection.Remove(container); container.Selected = false; } /// <summary> /// Process single click on a tree item /// /// Normally just select an item /// /// SHIFT-Click extends selection /// CTRL-Click toggles a selection /// </summary> /// <param name="sender"></param> private void OnTreeSingleClick(object sender) { FrameworkElement element = sender as FrameworkElement; if (element != null) { Container container = element.DataContext as Container; if (container != null) { if (CtrlPressed) { if (container.Selected) { RemoveFromSelection(container); } else { AddToSelection(container); } } else if (ShiftPressed) { if (container.Parent == m_first.Parent) { if (container.Index < m_first.Index) { Container item = container; for (int i = container.Index; i < m_first.Index; i++) { AddToSelection(item); item = item.Next; if (item == null) { break; } } } else if (container.Index > m_first.Index) { Container item = m_first; for (int i = m_first.Index; i <= container.Index; i++) { AddToSelection(item); item = item.Next; if (item == null) { break; } } } } } else { DeselectAndClear(); m_first = container; AddToSelection(container); } } } } /// <summary> /// Process double click on tree item /// </summary> /// <param name="sender"></param> private void OnTreeDoubleClick(object sender) { FrameworkElement element = sender as FrameworkElement; if (element != null) { Container container = element.DataContext as Container; if (container != null) { container.Editing = true; m_current = container.Name; } } } /// <summary> /// Clicked on the stack panel in the tree view /// /// Double left click: /// /// Switch to editing mode (flips visibility of textblock and textbox) /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTreeMouseDown(object sender, MouseButtonEventArgs e) { Debug.WriteLine("StackPanel mouse down"); switch(e.ChangedButton) { case MouseButton.Left: switch (e.ClickCount) { case 2: OnTreeDoubleClick(sender); e.Handled = true; break; } break; } } /// <summary> /// Clicked on tree view item in tree /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTreePreviewMouseDown(object sender, MouseButtonEventArgs e) { Debug.WriteLine("TreeViewItem preview mouse down"); switch (e.ChangedButton) { case MouseButton.Left: switch (e.ClickCount) { case 1: { // We've had a single click on a tree view item // Unfortunately this is the WHOLE tree item, including the +/- // symbol to the left. The tree doesn't do a selection, so we // have to filter this out... MouseDevice device = e.Device as MouseDevice; Debug.WriteLine(String.Format("Tree item clicked on: {0}", device.DirectlyOver.GetType().ToString())); // This is bad. The whole point of WPF is for the code // not to know what the UI has - yet here we are testing for // it as a workaround. Sigh... if (device.DirectlyOver.GetType() != typeof(Path)) { OnTreeSingleClick(sender); } // Cannot say handled - if we do it stops the tree working! //e.Handled = true; } break; } break; } } /// <summary> /// Key press in text box /// /// Return key finishes editing /// Escape key finishes editing, restores original value (this doesn't work!) /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTextBoxKeyDown(object sender, KeyEventArgs e) { switch(e.Key) { case Key.Return: { TextBox box = sender as TextBox; if (box != null) { Container container = box.DataContext as Container; if (container != null) { container.Editing = false; e.Handled = true; } } } break; case Key.Escape: { TextBox box = sender as TextBox; if (box != null) { Container container = box.DataContext as Container; if (container != null) { container.Editing = false; container.Name = m_current; e.Handled = true; } } } break; } } /// <summary> /// When text box becomes visible, grab focus and select all text in it. /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTextBoxIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e) { bool visible = (bool)e.NewValue; if (visible) { TextBox box = sender as TextBox; if (box != null) { box.Focus(); box.SelectAll(); } } } } Here's the Container class public class Container : INotifyPropertyChanged { private string m_name; private ObservableCollection<Container> m_children; private Container m_parent; private bool m_selected; private bool m_editing; /// <summary> /// Constructor /// </summary> /// <param name="name">name of object</param> public Container(string name) { m_name = name; m_children = new ObservableCollection<Container>(); m_parent = null; m_selected = false; m_editing = false; } /// <summary> /// Name of object /// </summary> public string Name { get { return m_name; } set { if (m_name != value) { m_name = value; OnPropertyChanged("Name"); } } } /// <summary> /// Index of object in parent's children /// /// If there's no parent, the index is -1 /// </summary> public int Index { get { if (m_parent != null) { return m_parent.Children.IndexOf(this); } return -1; } } /// <summary> /// Get the next item, assuming this is parented /// /// Returns null if end of list reached, or no parent /// </summary> public Container Next { get { if (m_parent != null) { int index = Index + 1; if (index < m_parent.Children.Count) { return m_parent.Children[index]; } } return null; } } /// <summary> /// List of children /// </summary> public ObservableCollection<Container> Children { get { return m_children; } } /// <summary> /// Selected status /// </summary> public bool Selected { get { return m_selected; } set { if (m_selected != value) { m_selected = value; OnPropertyChanged("Selected"); } } } /// <summary> /// Editing status /// </summary> public bool Editing { get { return m_editing; } set { if (m_editing != value) { m_editing = value; OnPropertyChanged("Editing"); } } } /// <summary> /// Parent of this object /// </summary> public Container Parent { get { return m_parent; } set { m_parent = value; } } /// <summary> /// WPF Property Changed event /// </summary> public event PropertyChangedEventHandler PropertyChanged; /// <summary> /// Handler to inform WPF that a property has changed /// </summary> /// <param name="name"></param> private void OnPropertyChanged(string name) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(name)); } } /// <summary> /// Add a child to this container /// </summary> /// <param name="child"></param> public void Add(Container child) { m_children.Add(child); child.m_parent = this; } /// <summary> /// Remove a child from this container /// </summary> /// <param name="child"></param> public void Remove(Container child) { m_children.Remove(child); child.m_parent = null; } } The two classes VisibilityConverter and VisibilityInverter are implementations of IValueConverter that translates bool to Visibility. They make sure the TextBlock is displayed when not editing, and the TextBox is displayed when editing.

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• These are few objective type questions which i was not able to find the solution [closed]

  - by Tarun

  1. Which of the following advantages does System.Collections.IDictionaryEnumerator provide over System.Collections.IEnumerator? a. It adds properties for direct access to both the Key and the Value b. It is optimized to handle the structure of a Dictionary. c. It provides properties to determine if the Dictionary is enumerated in Key or Value order d. It provides reverse lookup methods to distinguish a Key from a specific Value 2. When Implementing System.EnterpriseServices.ServicedComponent derived classes, which of the following statements are true? a. Enabling object pooling requires an attribute on the class and the enabling of pooling in the COM+ catalog. b. Methods can be configured to automatically mark a transaction as complete by the use of attributes. c. You can configure authentication using the AuthenticationOption when the ActivationMode is set to Library. d. You can control the lifecycle policy of an individual instance using the SetLifetimeService method. 3. Which of the following are true regarding event declaration in the code below? class Sample { event MyEventHandlerType MyEvent; } a. MyEventHandlerType must be derived from System.EventHandler or System.EventHandler<TEventArgs> b. MyEventHandlerType must take two parameters, the first of the type Object, and the second of a class derived from System.EventArgs c. MyEventHandlerType may have a non-void return type d. If MyEventHandlerType is a generic type, event declaration must use a specialization of that type. e. MyEventHandlerType cannot be declared static 4. Which of the following statements apply to developing .NET code, using .NET utilities that are available with the SDK or Visual Studio? a. Developers can create assemblies directly from the MSIL Source Code. b. Developers can examine PE header information in an assembly. c. Developers can generate XML Schemas from class definitions contained within an assembly. d. Developers can strip all meta-data from managed assemblies. e. Developers can split an assembly into multiple assemblies. 5. Which of the following characteristics do classes in the System.Drawing namespace such as Brush,Font,Pen, and Icon share? a. They encapsulate native resource and must be properly Disposed to prevent potential exhausting of resources. b. They are all MarshalByRef derived classes, but functionality across AppDomains has specific limitations. c. You can inherit from these classes to provide enhanced or customized functionality 6. Which of the following are required to be true by objects which are going to be used as keys in a System.Collections.HashTable? a. They must handle case-sensitivity identically in both the GetHashCode() and Equals() methods. b. Key objects must be immutable for the duration they are used within a HashTable. c. Get HashCode() must be overridden to provide the same result, given the same parameters, regardless of reference equalityl unless the HashTable constructor is provided with an IEqualityComparer parameter. d. Each Element in a HashTable is stored as a Key/Value pair of the type System.Collections.DictionaryElement e. All of the above 7. Which of the following are true about Nullable types? a. A Nullable type is a reference type. b. A Nullable type is a structure. c. An implicit conversion exists from any non-nullable value type to a nullable form of that type. d. An implicit conversion exists from any nullable value type to a non-nullable form of that type. e. A predefined conversion from the nullable type S? to the nullable type T? exists if there is a predefined conversion from the non-nullable type S to the non-nullable type T 8. When using an automatic property, which of the following statements is true? a. The compiler generates a backing field that is completely inaccessible from the application code. b. The compiler generates a backing field that is a private instance member with a leading underscore that can be programmatically referenced. c. The compiler generates a backing field that is accessible via reflection d. The compiler generates a code that will store the information separately from the instance to ensure its security. 9. Which of the following does using Initializer Syntax with a collection as shown below require? CollectionClass numbers = new CollectionClass { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; a. The Collection Class must implement System.Collections.Generic.ICollection<T> b. The Collection Class must implement System.Collections.Generic.IList<T> c. Each of the Items in the Initializer List will be passed to the Add<T>(T item) method d. The items in the initializer will be treated as an IEnumerable<T> and passed to the collection constructor+K110 10. What impact will using implicitly typed local variables as in the following example have? var sample = "Hello World"; a. The actual type is determined at compilation time, and has no impact on the runtime b. The actual type is determined at runtime, and late binding takes effect c. The actual type is based on the native VARIANT concept, and no binding to a specific type takes place. d. "var" itself is a specific type defined by the framework, and no special binding takes place 11. Which of the following is not supported by remoting object types? a. well-known singleton b. well-known single call c. client activated d. context-agile 12. In which of the following ways do structs differ from classes? a. Structs can not implement interfaces b. Structs cannot inherit from a base struct c. Structs cannot have events interfaces d. Structs cannot have virtual methods 13. Which of the following is not an unboxing conversion? a. void Sample1(object o) { int i = (int)o; } b. void Sample1(ValueType vt) { int i = (int)vt; } c. enum E { Hello, World} void Sample1(System.Enum et) { E e = (E) et; } d. interface I { int Value { get; set; } } void Sample1(I vt) { int i = vt.Value; } e. class C { public int Value { get; set; } } void Sample1(C vt) { int i = vt.Value; } 14. Which of the following are characteristics of the System.Threading.Timer class? a. The method provided by the TimerCallback delegate will always be invoked on the thread which created the timer. b. The thread which creates the timer must have a message processing loop (i.e. be considered a UI thread) c. The class contains protection to prevent reentrancy to the method provided by the TimerCallback delegate d. You can receive notification of an instance being Disposed by calling an overload of the Dispose method. 15. What is the proper declaration of a method which will handle the following event? Class MyClass { public event EventHandler MyEvent; } a. public void A_MyEvent(object sender, MyArgs e) { } b. public void A_MyEvent(object sender, EventArgs e) { } c. public void A_MyEvent(MyArgs e) { } d. public void A_MyEvent(MyClass sender,EventArgs e) { } 16. Which of the following scenarios are applicable to Window Workflow Foundation? a. Document-centric workflows b. Human workflows c. User-interface page flows d. Builtin support for communications across multiple applications and/or platforms e. All of the above 17. When using an automatic property, which of the following statements is true? a. The compiler generates a backing field that is completely inaccessible from the application code. b. The compiler generates a backing field that is a private instance member with a leading underscore that can be programmatically referenced. c. The compiler generates a backing field that is accessible via reflection d. The compiler generates a code that will store the information separately from the instance to ensure its security. 18 While using the capabilities supplied by the System.Messaging classes, which of the following are true? a. Information must be explicitly converted to/from a byte stream before it uses the MessageQueue class b. Invoking the MessageQueue.Send member defaults to using the System.Messaging.XmlMessageFormatter to serialize the object. c. Objects must be XMLSerializable in order to be transferred over a MessageQueue instance. d. The first entry in a MessageQueue must be removed from the queue before the next entry can be accessed e. Entries removed from a MessageQueue within the scope of a transaction, will be pushed back into the front of the queue if the transaction fails. 19. Which of the following are true about declarative attributes? a. They must be inherited from the System.Attribute. b. Attributes are instantiated at the same time as instances of the class to which they are applied. c. Attribute classes may be restricted to be applied only to application element types. d. By default, a given attribute may be applied multiple times to the same application element. 20. When using version 3.5 of the framework in applications which emit a dynamic code, which of the following are true? a. A Partial trust code can not emit and execute a code b. A Partial trust application must have the SecurityCriticalAttribute attribute have called Assert ReflectionEmit permission c. The generated code no more permissions than the assembly which emitted it. d. It can be executed by calling System.Reflection.Emit.DynamicMethod( string name, Type returnType, Type[] parameterTypes ) without any special permissions Within Windows Workflow Foundation, Compensating Actions are used for: a. provide a means to rollback a failed transaction b. provide a means to undo a successfully committed transaction later c. provide a means to terminate an in process transaction d. achieve load balancing by adapting to the current activity 21. What is the proper declaration of a method which will handle the following event? Class MyClass { public event EventHandler MyEvent; } a. public void A_MyEvent(object sender, MyArgs e) { } b. public void A_MyEvent(object sender, EventArgs e) { } c. public void A_MyEvent(MyArgs e) { } d. public void A_MyEvent(MyClass sender,EventArgs e) { } 22. Which of the following controls allows the use of XSL to transform XML content into formatted content? a. System.Web.UI.WebControls.Xml b. System.Web.UI.WebControls.Xslt c. System.Web.UI.WebControls.Substitution d. System.Web.UI.WebControls.Transform 23. To which of the following do automatic properties refer? a. You declare (explicitly or implicitly) the accessibility of the property and get and set accessors, but do not provide any implementation or backing field b. You attribute a member field so that the compiler will generate get and set accessors c. The compiler creates properties for your class based on class level attributes d. They are properties which are automatically invoked as part of the object construction process 24. Which of the following are true about Nullable types? a. A Nullable type is a reference type. b. An implicit conversion exists from any non-nullable value type to a nullable form of that type. c. A predefined conversion from the nullable type S? to the nullable type T? exists if there is a predefined conversion from the non-nullable type S to the non-nullable type T 25. When using an automatic property, which of the following statements is true? a. The compiler generates a backing field that is completely inaccessible from the application code. b. The compiler generates a backing field that is accessible via reflection. c. The compiler generates a code that will store the information separately from the instance to ensure its security. 26. When using an implicitly typed array, which of the following is most appropriate? a. All elements in the initializer list must be of the same type. b. All elements in the initializer list must be implicitly convertible to a known type which is the actual type of at least one member in the initializer list c. All elements in the initializer list must be implicitly convertible to common type which is a base type of the items actually in the list 27. Which of the following is false about anonymous types? a. They can be derived from any reference type. b. Two anonymous types with the same named parameters in the same order declared in different classes have the same type. c. All properties of an anonymous type are read/write. 28. Which of the following are true about Extension methods. a. They can be declared either static or instance members b. They must be declared in the same assembly (but may be in different source files) c. Extension methods can be used to override existing instance methods d. Extension methods with the same signature for the same class may be declared in multiple namespaces without causing compilation errors

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• An easy way to create Side by Side registrationless COM Manifests with Visual Studio

  - by Rick Strahl

  Here's something I didn't find out until today: You can use Visual Studio to easily create registrationless COM manifest files for you with just a couple of small steps. Registrationless COM lets you use COM component without them being registered in the registry. This means it's possible to deploy COM components along with another application using plain xcopy semantics. To be sure it's rarely quite that easy - you need to watch out for dependencies - but if you know you have COM components that are light weight and have no or known dependencies it's easy to get everything into a single folder and off you go. Registrationless COM works via manifest files which carry the same name as the executable plus a .manifest extension (ie. yourapp.exe.manifest) I'm going to use a Visual FoxPro COM object as an example and create a simple Windows Forms app that calls the component - without that component being registered. Let's take a walk down memory lane… Create a COM Component I start by creating a FoxPro COM component because that's what I know and am working with here in my legacy environment. You can use VB classic or C++ ATL object if that's more to your liking. Here's a real simple Fox one: DEFINE CLASS SimpleServer as Session OLEPUBLIC FUNCTION HelloWorld(lcName) RETURN "Hello " + lcName ENDDEFINE Compile it into a DLL COM component with: BUILD MTDLL simpleserver FROM simpleserver RECOMPILE And to make sure it works test it quickly from Visual FoxPro: server = CREATEOBJECT("simpleServer.simpleserver") MESSAGEBOX( server.HelloWorld("Rick") ) Using Visual Studio to create a Manifest File for a COM Component Next open Visual Studio and create a new executable project - a Console App or WinForms or WPF application will all do. Go to the References Node Select Add Reference Use the Browse tab and find your compiled DLL to import  Next you'll see your assembly in the project. Right click on the reference and select Properties Click on the Isolated DropDown and select True Compile and that's all there's to it. Visual Studio will create a App.exe.manifest file right alongside your application's EXE. The manifest file created looks like this: xml version="1.0" encoding="utf-8"? assembly xsi:schemaLocation="urn:schemas-microsoft-com:asm.v1 assembly.adaptive.xsd" manifestVersion="1.0" xmlns:asmv1="urn:schemas-microsoft-com:asm.v1" xmlns:asmv2="urn:schemas-microsoft-com:asm.v2" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#" xmlns:co.v1="urn:schemas-microsoft-com:clickonce.v1" xmlns:co.v2="urn:schemas-microsoft-com:clickonce.v2" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" assemblyIdentity name="App.exe" version="1.0.0.0" processorArchitecture="x86" type="win32" / file name="simpleserver.DLL" asmv2:size="27293" hash xmlns="urn:schemas-microsoft-com:asm.v2" dsig:Transforms dsig:Transform Algorithm="urn:schemas-microsoft-com:HashTransforms.Identity" / dsig:Transforms dsig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" / dsig:DigestValuepuq+ua20bbidGOWhPOxfquztBCU=dsig:DigestValue hash typelib tlbid="{f10346e2-c9d9-47f7-81d1-74059cc15c3c}" version="1.0" helpdir="" resourceid="0" flags="HASDISKIMAGE" / comClass clsid="{af2c2811-0657-4264-a1f5-06d033a969ff}" threadingModel="Apartment" tlbid="{f10346e2-c9d9-47f7-81d1-74059cc15c3c}" progid="simpleserver.SimpleServer" description="simpleserver.SimpleServer" / file assembly Now let's finish our super complex console app to test with: using System; using System.Collections.Generic; using System.Text; namespace ConsoleApplication1 {     class Program     {         static voidMain(string[] args)         { Type type = Type.GetTypeFromProgID("simpleserver.simpleserver",true); dynamic server = Activator.CreateInstance(type); Console.WriteLine(server.HelloWorld("rick")); Console.ReadLine(); } } } Now run the Console Application… As expected that should work. And why not? The COM component is still registered, right? :-) Nothing tricky about that. Let's unregister the COM component and then re-run and see what happens. Go to the Command Prompt Change to the folder where the DLL is installed Unregister with: RegSvr32 -u simpleserver.dll      To be sure that the COM component no longer works, check it out with the same test you used earlier (ie. o = CREATEOBJECT("SimpleServer.SimpleServer") in your development environment or VBScript etc.). Make sure you run the EXE and you don't re-compile the application or else Visual Studio will complain that it can't find the COM component in the registry while compiling. In fact now that we have our .manifest file you can remove the COM object from the project. When you run run the EXE from Windows Explorer or a command prompt to avoid the recompile. Watch out for embedded Manifest Files Now recompile your .NET project and run it… and it will most likely fail! The problem is that .NET applications by default embeds a manifest file into the compiled EXE application which results in the externally created manifest file being completely ignored. Only one manifest can be applied at a time and the compiled manifest takes precedency. Uh, thanks Visual Studio - not very helpful… Note that if you use another development tool like Visual FoxPro to create your EXE this won't be an issue as long as the tool doesn't automatically add a manifest file. Creating a Visual FoxPro EXE for example will work immediately with the generated manifest file as is. If you are using .NET and Visual Studio you have a couple of options of getting around this: Remove the embedded manifest file Copy the contents of the generated manifest file into a project manifest file and compile that in To remove an embedded manifest in a Visual Studio project: Open the Project Properties (Alt-Enter on project node) Go down to Resources | Manifest and select | Create Application without a Manifest   You can now add use the external manifest file and it will actually be respected when the app runs. The other option is to let Visual Studio create the manifest file on disk and then explicitly add the manifest file into the project. Notice on the dialog above I did this for app.exe.manifest and the manifest actually shows up in the list. If I select this file it will be compiled into the EXE and be used in lieu of any external files and that works as well. Remove the simpleserver.dll reference so you can compile your code and run the application. Now it should work without COM registration of the component. Personally I prefer external manifests because they can be modified after the fact - compiled manifests are evil in my mind because they are immutable - once they are there they can't be overriden or changed. So I prefer an external manifest. However, if you are absolutely sure nothing needs to change and you don't want anybody messing with your manifest, you can also embed it. The option to either is there. Watch for Manifest Caching While working trying to get this to work I ran into some problems at first. Specifically when it wasn't working at first (due to the embedded schema) I played with various different manifest layouts in different files etc.. There are a number of different ways to actually represent manifest files including offloading to separate folder (more on that later). A few times I made deliberate errors in the schema file and I found that regardless of what I did once the app failed or worked no amount of changing of the manifest file would make it behave differently. It appears that Windows is caching the manifest data for a given EXE or DLL. It takes a restart or a recompile of either the EXE or the DLL to clear the caching. Recompile your servers in order to see manifest changes unless there's an outright failure of an invalid manifest file. If the app starts the manifest is being read and caches immediately. This can be very confusing especially if you don't know that it's happening. I found myself always recompiling the exe after each run and before making any changes to the manifest file. Don't forget about Runtimes of COM Objects In the example I used above I used a Visual FoxPro COM component. Visual FoxPro is a runtime based environment so if I'm going to distribute an application that uses a FoxPro COM object the runtimes need to be distributed as well. The same is true of classic Visual Basic applications. Assuming that you don't know whether the runtimes are installed on the target machines make sure to install all the additional files in the EXE's directory alongside the COM DLL. In the case of Visual FoxPro the target folder should contain: The EXE  App.exe The Manifest file (unless it's compiled in) App.exe.manifest The COM object DLL (simpleserver.dll) Visual FoxPro Runtimes: VFP9t.dll (or VFP9r.dll for non-multithreaded dlls), vfp9rENU.dll, msvcr71.dll All these files should be in the same folder. Debugging Manifest load Errors If you for some reason get your manifest loading wrong there are a couple of useful tools available - SxSTrace and SxSParse. These two tools can be a huge help in debugging manifest loading errors. Put the following into a batch file (SxS_Trace.bat for example): sxstrace Trace -logfile:sxs.bin sxstrace Parse -logfile:sxs.bin -outfile:sxs.txt Then start the batch file before running your EXE. Make sure there's no caching happening as described in the previous section. For example, if I go into the manifest file and explicitly break the CLSID and/or ProgID I get a detailed report on where the EXE is looking for the manifest and what it's reading. Eventually the trace gives me an error like this: INFO: Parsing Manifest File C:\wwapps\Conf\SideBySide\Code\app.EXE.     INFO: Manifest Definition Identity is App.exe,processorArchitecture="x86",type="win32",version="1.0.0.0".     ERROR: Line 13: The value {AAaf2c2811-0657-4264-a1f5-06d033a969ff} of attribute clsid in element comClass is invalid. ERROR: Activation Context generation failed. End Activation Context Generation. pinpointing nicely where the error lies. Pay special attention to the various attributes - they have to match exactly in the different sections of the manifest file(s). Multiple COM Objects The manifest file that Visual Studio creates is actually quite more complex than is required for basic registrationless COM object invokation. The manifest file can be simplified a lot actually by stripping off various namespaces and removing the type library references altogether. Here's an example of a simplified manifest file that actually includes references to 2 COM servers: xml version="1.0" encoding="utf-8"? assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0" assemblyIdentity name="App.exe" version="1.0.0.0" processorArchitecture="x86" type="win32" / file name="simpleserver.DLL" comClass clsid="{af2c2811-0657-4264-a1f5-06d033a969ff}" threadingModel="Apartment" progid="simpleserver.SimpleServer" description="simpleserver.SimpleServer" / file file name = "sidebysidedeploy.dll" comClass clsid="{EF82B819-7963-4C36-9443-3978CD94F57C}" progid="sidebysidedeploy.SidebysidedeployServer" description="SidebySideDeploy Server" threadingModel="apartment" / file assembly Simple enough right? Routing to separate Manifest Files and Folders In the examples above all files ended up in the application's root folder - all the DLLs, support files and runtimes. Sometimes that's not so desirable and you can actually create separate manifest files. The easiest way to do this is to create a manifest file that 'routes' to another manifest file in a separate folder. Basically you create a new 'assembly identity' via a named id. You can then create a folder and another manifest with the id plus .manifest that points at the actual file. In this example I create: App.exe.manifest A folder called App.deploy A manifest file in App.deploy All DLLs and runtimes in App.deploy Let's start with that master manifest file. This file only holds a reference to another manifest file: App.exe.manifest xml version="1.0" encoding="UTF-8" standalone="yes"? assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0" assemblyIdentity name="App.exe" version="1.0.0.0" processorArchitecture="x86" type="win32" / dependency dependentAssembly assemblyIdentity name="App.deploy" version="1.0.0.0" type="win32" / dependentAssembly dependency assembly   Note this file only contains a dependency to App.deploy which is another manifest id. I can then create App.deploy.manifest in the current folder or in an App.deploy folder. In this case I'll create App.deploy and in it copy the DLLs and support runtimes. I then create App.deploy.manifest. App.deploy.manifest xml version="1.0" encoding="UTF-8" standalone="yes"? assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0" assemblyIdentity name="App.deploy" type="win32" version="1.0.0.0" / file name="simpleserver.DLL" comClass clsid="{af2c2811-0657-4264-a1f5-06d033a969ff}" threadingModel="Apartment" progid="simpleserver.SimpleServer" description="simpleserver.SimpleServer" / file file name="sidebysidedeploy.dll" comClass clsid="{EF82B819-7963-4C36-9443-3978CD94F57C}" threadingModel="Apartment" progid="sidebysidedeploy.SidebysidedeployServer" description="SidebySideDeploy Server" / file assembly   In this manifest file I then host my COM DLLs and any support runtimes. This is quite useful if you have lots of DLLs you are referencing or if you need to have separate configuration and application files that are associated with the COM object. This way the operation of your main application and the COM objects it interacts with is somewhat separated. You can see the two folders here:   Routing Manifests to different Folders In theory registrationless COM should be pretty easy in painless - you've seen the configuration manifest files and it certainly doesn't look very complicated, right? But the devil's in the details. The ActivationContext API (SxS - side by side activation) is very intolerant of small errors in the XML or formatting of the keys, so be really careful when setting up components, especially if you are manually editing these files. If you do run into trouble SxsTrace/SxsParse are a huge help to track down the problems. And remember that if you do have problems that you'll need to recompile your EXEs or DLLs for the SxS APIs to refresh themselves properly. All of this gets even more fun if you want to do registrationless COM inside of IIS :-) But I'll leave that for another blog post…© Rick Strahl, West Wind Technologies, 2005-2011Posted in COM  .NET  FoxPro   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Creating an ASP.NET report using Visual Studio 2010 - Part 3

  - by rajbk

  We continue building our report in this three part series. Creating an ASP.NET report using Visual Studio 2010 - Part 1 Creating an ASP.NET report using Visual Studio 2010 - Part 2 Adding the ReportViewer control and filter drop downs. Open the source code for index.aspx and add a ScriptManager control. This control is required for the ReportViewer control. Add a DropDownList for the categories and suppliers. Add the ReportViewer control. The markup after these steps is shown below. <div> <asp:ScriptManager ID="smScriptManager" runat="server"> </asp:ScriptManager> <div id="searchFilter"> Filter by: Category : <asp:DropDownList ID="ddlCategories" runat="server" /> and Supplier : <asp:DropDownList ID="ddlSuppliers" runat="server" /> </div> <rsweb:ReportViewer ID="rvProducts" runat="server"> </rsweb:ReportViewer> </div> The design view for index.aspx is shown below. The dropdowns will display the categories and suppliers in the database. Changing the selection in the drop downs will cause the report to be filtered by the selections in the dropdowns. You will see how to do this in the next steps.   Attaching the RDLC to the ReportViewer control by clicking on the top right of the control, going to Report Viewer tasks and selecting Products.rdlc.   Resize the ReportViewer control by dragging at the bottom right corner. I set mine to 800px x 500px. You can also set this value in source view. Defining the data sources. We will now define the Data Source used to populate the report. Go back to the “ReportViewer Tasks” and select “Choose Data Sources” Select a “New data source..” Select “Object” and name your Data Source ID “odsProducts”   In the next screen, choose “ProductRepository” as your business object. Choose “GetProductsProjected” in the next screen.   The method requires a SupplierID and CategoryID. We will set these so that our data source gets the values from the drop down lists we defined earlier. Set the parameter source to be of type “Control” and set the ControlIDs to be ddlSuppliers and ddlCategories respectively. Your screen will look like this: We are now going to define the data source for our drop downs. Select the ddlCategory drop down and pick “Choose Data Source”. Pick “Object” and give it an id “odsCategories”   In the next screen, choose “ProductRepository” Select the GetCategories() method in the next screen.   Select “CategoryName” and “CategoryID” in the next screen. We are done defining the data source for the Category drop down. Perform the same steps for the Suppliers drop down.   Select each dropdown and set the AppendDataBoundItems to true and AutoPostback to true.     The AppendDataBoundItems is needed because we are going to insert an “All“ list item with a value of empty. Go to each drop down and add this list item markup as shown below> Finally, double click on each drop down in the designer and add the following code in the code behind. This along with the “Autopostback= true” attribute refreshes the report anytime a drop down is changed. protected void ddlCategories_SelectedIndexChanged(object sender, EventArgs e) { rvProducts.LocalReport.Refresh(); }   protected void ddlSuppliers_SelectedIndexChanged(object sender, EventArgs e) { rvProducts.LocalReport.Refresh(); } Compile your report and run the page. You should see the report rendered. Note that the tool bar in the ReportViewer control gives you a couple of options including the ability to export the data to Excel, PDF or word.   Conclusion Through this three part series, we did the following: Created a data layer for use by our RDLC. Created an RDLC using the report wizard and define a dataset for the report. Used the report design surface to design our report including adding a chart. Used the ReportViewer control to attach the RDLC. Connected our ReportWiewer to a data source and take parameter values from the drop downlists. Used AutoPostBack to refresh the reports when the dropdown selection was changed. RDLCs allow you to create interactive reports including drill downs and grouping. For even more advanced reports you can use Microsoft® SQL Server™ Reporting Services with RDLs. With RDLs, the report is rendered on the report server instead of the web server. Another nice thing about RDLs is that you can define a parameter list for the report and it gets rendered automatically for you. RDLCs and RDLs both have their advantages and its best to compare them and choose the right one for your requirements. Download VS2010 RTM Sample project NorthwindReports.zip   Alfred Borden: Are you watching closely?

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• Entity Framework 4.0: Creating objects of correct type when using lazy loading

  - by DigiMortal

  In my posting about Entity Framework 4.0 and POCOs I introduced lazy loading in EF applications. EF uses proxy classes for lazy loading and this means we have new types in that come and go dynamically in runtime. We don’t have these types available when we write code but we cannot forget that EF may expect us to use dynamically generated types. In this posting I will give you simple hint how to use correct types in your code. The background of lazy loading and proxy classes As a first thing I will explain you in short what is proxy class. Business classes when designed correctly have no knowledge about their birth and death – they don’t know how they are created and they don’t know how their data is persisted. This is the responsibility of object runtime. When we use lazy loading we need a little bit different classes that know how to load data for properties when code accesses the property first time. As we cannot add this functionality to our business classes (they may be stored through more than one data access technology or by more than one Data Access Layer (DAL)) we create proxy classes that extend our business classes. If we have class called Product and product has lazy loaded property called Customer then we need proxy class, let’s say ProductProxy, that has same public signature as Product so we can use it INSTEAD OF product in our code. ProductProxy overrides Customer property. If customer is not asked then customer is null. But if we ask for Customer property then overridden property of ProductProxy loads it from database. This is how lazy loading works. Problem – two types for same thing As lazy loading may introduce dynamically generated proxy types we don’t know in our application code which type is returned. We cannot be sure that we have Product not ProductProxy returned. This leads us to the following question: how can we create Product of correct type if we don’t know the correct type? In EF solution is simple. Solution – use factory methods If you are using repositories and you are not using factories (imho it is pretty pointless with mapper) you can add factory methods to your EF based repositories. Take a look at this class. public class Event {     public int ID { get; set; }     public string Title { get; set; }     public string Location { get; set; }     public virtual Party Organizer { get; set; }     public DateTime Date { get; set; } } We have virtual member called Organizer. This property is virtual because we want to use lazy loading on this class so Organizer is loaded only when we ask it. EF provides us with method called CreateObject<T>(). CreateObject<T>() is member of ObjectContext class and it creates the object based on given type. In runtime proxy type for Event is created for us automatically and when we call CreateObject<T>() for Event it returns as object of Event proxy type. The factory method for events repository is as follows. public Event CreateEvent() {     var evt = _context.CreateObject<Event>();     return evt; } And we are done. Instead of creating factory classes we created factory methods that guarantee that created objects are of correct type. Conclusion Although lazy loading introduces some new objects we cannot use at design time because they live only in runtime we can write code without worrying about exact implementation type of object. This holds true until we have clean code and we don’t make any decisions based on object type. EF4.0 provides us with very simple factory method that create and return objects of correct type. All we had to do was adding factory methods to our repositories.

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• Workaround for datadude deployment bug - NullReferenceException

  - by jamiet

  I have come across a bug in Visual Studio 2010 Database Projects (aka datadude aka DPro aka Visual Studio Database Development Tools aka Visual Studio Team Edition for Database Professionals aka Juneau aka SQL Server Data Tools) that other people may encounter so, for the purposes of googling, I'm writing this blog post about it. Through my own googling I discovered that a Connect bug had already been raised about it (VS2010 Database project deploy - “SqlDeployTask” task failed unexpectedly, NullReferenceException), and coincidentally enough it was raised by my former colleague Tom Hunter (whom I have mentioned here before as the superhuman Tom Hunter) although it has not (at this time) received a reply from Microsoft. Tom provided a repro, namely that this syntactically valid function definition: CREATE FUNCTION [dbo].[Function1]()RETURNS TABLEASRETURN (    WITH cte AS (    SELECT 1 AS [c1]    FROM [$(Database3)].[dbo].[Table1]   )   SELECT 1 AS [c1]   FROM cte) would produce this nasty unhelpful error upon deployment: C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\TeamData\Microsoft.Data.Schema.TSqlTasks.targets(120,5): Error MSB4018: The "SqlDeployTask" task failed unexpectedly.System.NullReferenceException: Object reference not set to an instance of an object.   at Microsoft.Data.Schema.Sql.SchemaModel.SqlModelComparerBase.VariableSubstitution(SqlScriptProperty propertyValue, IDictionary`2 variables, Boolean& isChanged)   at Microsoft.Data.Schema.Sql.SchemaModel.SqlModelComparerBase.ArePropertiesEqual(IModelElement source, IModelElement target, ModelPropertyClass propertyClass, ModelComparerConfiguration configuration)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareProperties(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithoutCompareName(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithSameType(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean ignoreComparingName, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, Boolean compareFromRootElement, ModelComparisonChangeDefinition& changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareChildren(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareParentElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes, Boolean isComposing)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithoutCompareName(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithSameType(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean ignoreComparingName, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, Boolean compareFromRootElement, ModelComparisonChangeDefinition& changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareChildren(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareParentElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes, Boolean isComposing)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithoutCompareName(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithSameType(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean ignoreComparingName, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, Boolean compareFromRootElement, ModelComparisonChangeDefinition& changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareAllElementsForOneType(ModelElementClass type, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean compareOrphanedElements)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareStore(ModelStore source, ModelStore target, ModelComparerConfiguration configuration)   at Microsoft.Data.Schema.Build.SchemaDeployment.CompareModels()   at Microsoft.Data.Schema.Build.SchemaDeployment.PrepareBuildPlan()   at Microsoft.Data.Schema.Build.SchemaDeployment.Execute(Boolean executeDeployment)   at Microsoft.Data.Schema.Build.SchemaDeployment.Execute()   at Microsoft.Data.Schema.Tasks.DBDeployTask.Execute()   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask, Boolean& taskResult)   Done executing task "SqlDeployTask" -- FAILED.  Done building target "DspDeploy" in project "Lloyds.UKTax.DB.UKtax.dbproj" -- FAILED. Done executing task "CallTarget" -- FAILED.Done building target "DBDeploy" in project It turns out there are a certain set of circumstances that need to be met for this error to occur: The object being deployed is an inline function  (may also exist for multistatement and scalar functions - I haven't tested that) That object includes SQLCMD variable references The object has already been deployed successfully Just to reiterate that last bullet point, the error does not occur when you deploy the function for the first time, only on the subsequent deployment.   Luckily I have a direct line into a guy on the development team so I fired off an email on Friday evening and today (Monday) I received a reply back telling me that there is a simple fix, one simply has to remove the parentheses that wrap the SQL statement. So, in the case of Tom's repro, the function definition simpy has to be changed to: CREATE FUNCTION [dbo].[Function1]()RETURNS TABLEASRETURN --(    WITH cte AS (    SELECT 1 AS [c1]    FROM [$(Database3)].[dbo].[Table1]   )   SELECT 1 AS [c1]   FROM cte--) I have commented out the offending parentheses rather than removing them just to emphasize the point. Thereafter the function will deploy fine. I tested this out on my own project this morning and can confirm that this fix does indeed work.   I have been told that the bug CAN be reproduced in the Release Candidate (RC) 0 build of SQL Server Data Tools in SQL Server 2010 so am hoping that a fix makes it in for the Release-To-Manufacturing (RTM) build. Hope this helps @jamiet

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• Book Review: Oracle ADF Real World Developer’s Guide

  - by Frank Nimphius

  Recently PACKT Publishing published "Oracle ADF Real World Developer’s Guide" by Jobinesh Purushothaman, a product manager in our team. Though already the sixth book dedicated to Oracle ADF, it has a lot of great information in it that none of the previous books covered, making it a safe buy even for those who own the other books published by Oracle Press (McGrwHill) and PACKT Publishing. More than the half of the "Oracle ADF Real World Developer’s Guide" book is dedicated to Oracle ADF Business Components in a depth and clarity that allows you to feel the expertise that Jobinesh gained in this area. If you enjoy Jobinesh blog (http://jobinesh.blogspot.co.uk/) about Oracle ADF, then, no matter what expert you are in Oracle ADF, this book makes you happy as it provides you with detail information you always wished to have. If you are new to Oracle ADF, then this book alone doesn't get you flying, but, if you have some Java background, accelerates your learning big, big, big times. Chapter 1 is an introduction to Oracle ADF and not only explains the layers but also how it compares to plain Java EE solutions (page 13). If you are new to Oracle JDeveloper and ADF, then at the end of this chapter you know how to start JDeveloper and begin your ADF development Chapter 2 starts with what Jobinesh really is good at: ADF Business Components. In this chapter you learn about the architecture ingredients of ADF Business Components: View Objects, View Links, Associations, Entities, Row Sets, Query Collections and Application Modules. This chapter also provides a introduction to ADFBC SDO services, as well as sequence diagrams for what happens when you execute queries or commit updates. Chapter 3 is dedicated to entity objects and  is one of many chapters in this book you will enjoy and never want to miss. Jobinesh explains the artifacts that make up an entity object, how to work with entities and resource bundles, and many advanced topics, including inheritance, change history tracking, custom properties, validation and cursor handling.  Chapter 4 - you guessed it - is all about View objects. Comparable to entities, you learn about the XM files and classes that make a view object, as well as how to define and work with queries. List-of-values, inheritance, polymorphism, bind variables and data filtering are interesting - and important topics that follow. Again the chapter provides helpful sequence diagrams for you to understand what happens internally within a view object. Chapter 5 focuses on advanced view object and entity object topics, like lifecycle callback methods and when you want to override them. This chapter is a good digest of Jobinesh's blog entries (which most ADF developers have in their bookmark list). Really worth reading ! Chapter 6 then is bout Application Modules. Beside of what application modules are, this chapter covers important topics like properties, passivation, activation, application module pooling, how and where to write custom logic. In addition you learn about the AM lifecycle and request sequence. Chapter 7 is about the ADF binding layer. If you are new to Oracle ADF and got lost in the more advanced ADF Business Components chapters, then this chapter is where you get back into the game. In very easy terms, Jobinesh explains what the ADF binding is, how it fits into the JSF request lifecycle and what are the metadata file involved. Chapter 8 then goes into building data bound web user interfaces. In this chapter you get the basics of JavaServer Faces (e.g. managed beans) and learn about the interaction between the JSF UI and the ADF binding layer. Later this chapter provides advanced solutions for working with tree components and list of values. Chapter 9 introduces bounded task flows and ADF controller. This is a chapter you want to read if you are new to ADF of have started. Experts don't find anything new here, which doesn't mean that it is not worth reading it (I for example, enjoyed the controller talk very much) Chapter 10 is an advanced coverage of bounded task flow and talks about contextual events  Chapter 11 is another highlight and explains error handling, trains, transactions and more. I can only recommend you read this chapter. I am aware of many documents that cover exception handling in Oracle ADF (and my Oracle Magazine article for January/February 2013 does the same), but none that covers it in such a great depth. Chapter 12 covers ADF best practices, which is a great round-up of all the tips provided in this book (without Jobinesh to repeat himself). Its all cool stuff that helps you with your ADF projects. In summary, "Oracle ADF Real World Developer’s Guide" by Jobinesh Purushothaman is a great book and addition for all Oracle ADF developers and those who want to become one. Frank

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