XAML shouldn't really get in the way here.

<Object xmlns="clr-namespace:System;assembly=mscorlib" 
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        x:Class="Singleton" />

using System;

public partial class Singleton
{
    private static Singleton instance;

    private Singleton()
    {
        InitializeComponent();
    }

    public static Singleton Instance
    {
        get
        {
            if (instance == null)
            {
                instance = new Singleton();
            }
            return instance;
        }
    }
}

here is a brief instruction set for how to build a singleton xaml app from scratch.

Then you have to make your own modifications in your app.

follow the steps below

1. Run Visual Studio

2.From the menu Select File -> New Project ->Windows Application (WPF) then OK

3.Double click Window1.xaml.cs

4.Overwritethe partial class Window1 with the code below

XAML shouldn't really get in the way here.

<Object xmlns="clr-namespace:System;assembly=mscorlib" 
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        x:Class="Singleton" />

using System;

public partial class Singleton
{
    private static Singleton instance;

    private Singleton()
    {
        InitializeComponent();
    }

    public static Singleton Instance
    {
        get
        {
            if (instance == null)
            {
                instance = new Singleton();
            }
            return instance;
        }
    }
}

What if I want my window to be a singleton?

<Window x:Class="???">

You just need toreplace the XAML in my example above with:

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="Singleton" />

My code originally was:

<Window x:Class="UserControlTest.MainWindow"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Title="TITLE"

Height="662"

Width="1105"

ResizeMode="CanResizeWithGrip"

SnapsToDevicePixels="True">

Did what you said... set x:class to "Singleton"... I have errors such as "InitializeComponent" does not exist in the current context.

The class name specified by x:Class should alwaysmatch the name of the class in your codebehind file. In my example the class defined by the XAML and the codebehind were called Singleton.

I'm not really sure where you are going wrong. As I said, you don't need to do anything with the XAML to make itconform to thesingleton pattern, just the codebehind - and eventhere it's just as you would do with any other C# class.

I'm not understanding something I guess... here's my original code:

C#:

namespace UserControlTest

/// <summary>

/// Interaction logic for MainWindow.xaml. This window contains a canvas that other user

/// controls can be added to.

/// </summary>

public partial class MainWindow : Window

C#:

namespace UserControlTest

/// <summary>

/// Interaction logic for MainWindow.xaml. This window contains a canvas that other user

/// controls can be added to.

/// </summary>

public partial class MainWindow : Window

I now get:

Error9'UserControlTest.MainWindow' does not contain a definition for 'mainCanvas'C:\Documents and Settings\daszybr\Desktop\MDIApp\MDIUserControl.xaml.cs40244MDIApp

Error10The name 'InitializeComponent' does not exist in the current contextC:\Documents and Settings\daszybr\Desktop\MDIApp\MainWindow.xaml.cs6413MDIApp

.....

and several more errors on all the components of MainWindow...

I also tried

<Window x:Class="UserControlTest.MainWindow.Instance"....

.......

but then I get "Error8The namespace 'UserControlTest' already contains a definition for 'MainWindow'C:\Documents and Settings\daszybr\Desktop\MDIApp\MainWindow.xaml.cs2426MDIApp
"

here is a brief instruction set for how to build a singleton xaml app from scratch.

Then you have to make your own modifications in your app.

follow the steps below

1. Run Visual Studio

2.From the menu Select File -> New Project ->Windows Application (WPF) then OK

3.Double click Window1.xaml.cs

4.Overwritethe partial class Window1 with the code below

<Window x:Class="WindowsApplication1.Window1"....

Thanks.

Hello, I fallowed the same method you mentioned here. However, when I try to show the form after it has closed,I am getting "Cannot set Visibility or call Show or ShowDialog after window has closed.". In this sense error message is quite explainatory. Nevertheless I need a single instance child form which can be opened and closed as much as user needs. Please help meabout this matter.

Thanx,