I have a Window (MainWindow.xaml) which has a ViewModel (MainWindowViewModel.cs). I also have a UserControl called MyUserControl.xaml which also has a corresponding ViewModel (MyUserControlViewModel.cs).
I have inserted two instances of the UserControl into the MainWindow:
<Window x:Class="MyProject.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MyProject"
Title="My Window">
<Grid>
<local:MyUserControl Visibility="{Binding Path=MyUserControl1Visibility, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" />
<local:MyUserControl Visibility="{Binding Path=MyUserControl2Visibility, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" />
</Grid>
</Window>
In the CodeBehind of MainWindow I set the DataContext of the Window to an instance of the ViewModel:
public MainWindow()
{
InitializeComponent();
this.DataContext = new MainWindowViewModel();
}
MainWindowViewModel has the Visibility-properties that the MyUserControl-instances are bound to. They both look like this:
private Visibility _myUserControl1Visibility = Visibility.Collapsed;
public Visibility MyUserControl1Visibility
{
get
{
return _myUserControl1Visibility;
}
private set
{
if (value != _myUserControl1Visibility)
{
_myUserControl1Visibility = value;
OnPropertyChanged("MyUserControl1Visibility");
}
}
}
Furthermore, MainWindow and MainWindowViewModel has buttons and commands to enable the user to toggle between the two MyUserControl instances. That is, only one of them are shown at any time.
This worked fine… until the UserControls got their own ViewModels. Now the runtime tries to find the bound VisibilityProperties (MyUserControl1Visibility…) on the ViewModels of the UserControls instead of the ViewModel of MainWindow.
How do I make these bindings go to MainWindowViewModel instead of to the respective ViewModels of the UserControl instances?
The MyUserControls inherited the DataContext from MainWindow and that's why it works to begin with. When MyUserControl1 get a ViewModel of its own that will be its DataContext. Maybe this was clear to you :) To use the DataContext of the MainWindow in the binding instead you can use RelativeSource or name the Window and use ElementName
<local:MyUserControl Visibility="{Binding ElementName=mainWindow,
Path=DataContext.MyUserControl1Visibility,
Mode=OneWay,
UpdateSourceTrigger=PropertyChanged}" />
Visibility="{Binding RelativeSource={x:Static RelativeSource.Self},
Path=DataContext.MyUserControl1Visibility}"
Related
I created a small File Browser Control:
<UserControl x:Class="Test.UserControls.FileBrowserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="44" d:DesignWidth="461" Name="Control">
<Grid Margin="3">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<TextBox Margin="3" Text="{Binding SelectedFile}" IsReadOnly="True" TextWrapping="Wrap" />
<Button HorizontalAlignment="Right" Margin="3" Width="100" Content="Browse" Grid.Column="1" Command="{Binding BrowseCommand}" />
</Grid>
</UserControl>
With the following code behind:
public partial class FileBrowserControl : UserControl
{
public ICommand BrowseCommand { get; set; }
//The dependency property
public static DependencyProperty SelectedFileProperty = DependencyProperty.Register("SelectedFile",
typeof(string),typeof(FileBrowserControl), new PropertyMetadata(String.Empty));
public string SelectedFile { get{ return (string)GetValue(SelectedFileProperty);} set{ SetValue(SelectedFileProperty, value);}}
//For my first test, this is a static string
public string Filter { get; set; }
public FileBrowserControl()
{
InitializeComponent();
BrowseCommand = new RelayCommand(Browse);
Control.DataContext = this;
}
private void Browse()
{
SaveFileDialog dialog = new SaveFileDialog();
if (Filter != null)
{
dialog.Filter = Filter;
}
if (dialog.ShowDialog() == true)
{
SelectedFile = dialog.FileName;
}
}
}
And I use it like this:
<userControls:FileBrowserControl SelectedFile="{Binding SelectedFile}" Filter="XSLT File (*.xsl)|*.xsl|All Files (*.*)|*.*"/>
(SelectedFile is Property of the ViewModel of the usercontrol using this control)
Currently the issue is that when I click on Browse, the textbox in the usercontrol is correctly updating, but the SelectedFile property of the viewmodel parent control is not set(no call to the set property).
If I set the Mode of the binding to TwoWay, I got this exception:
An unhandled exception of type 'System.StackOverflowException' occurred in Unknown Module.
So what did I do wrong?
The problem is that you set your UserControl's DataContext to itself in its constructor:
DataContext = this;
You should not do that, because it breaks any DataContext based Bindings, i.e. to a view model instance that is provided by property value inheritance of the DataContext property
Instead you would change the binding in the UserControl's XAML like this:
<TextBox Text="{Binding SelectedFile,
RelativeSource={RelativeSource AncestorType=UserControl}}" />
Now, when you use your UserControl and write a binding like
<userControls:FileBrowserControl SelectedFile="{Binding SelectedFile}" />
the SelectedFile property gets bound to a SelectedFile property in your view model, which should be in the DataContext inherited from a parent control.
Do not ever set DataContext of UserControl inside usercontrol:
THIS IS WRONG:
this.DataContext = someDataContext;
because if somebody will use your usercontrol, its common practice to set its datacontext and it is in conflict with what you have set previously
<my:SomeUserControls DataContext="{Binding SomeDataContext}" />
Which one will be used? Well, it depends...
The same applies to Name property. you should not set name to UserControl like this:
<UserControl x:Class="WpfApplication1.SomeUserControl" Name="MyUserControl1" />
because it is in conflict with
<my:SomeUserControls Name="SomeOtherName" />
SOLUTION:
In your control, just use RelativeSource Mode=FindAncestor:
<TextBox Text="{Binding SelectedFile, RelativeSource={RelativeSource AncestorType="userControls:FileBrowserControl"}" />
To your question on how are all those third party controls done: They use TemplateBinding. But TemplateBinding can be used only in ControlTemplate. http://www.codeproject.com/Tips/599954/WPF-TemplateBinding-with-ControlTemplate
In usercontrol the xaml represents Content of UserControl, not ControlTemplate/
Using this:
<userControls:FileBrowserControl SelectedFile="{Binding SelectedFile}" ...
The FileBrowserControl's DataContext has already been set to itself, therefore you are effectively asking to bind to the SelectedFile where the DataContext is the FileBrowserControl, not the parent ViewModel.
Give your View a name and use an ElementName binding instead.
SelectedFile="{Binding DataContext.SelectedFile, ElementName=element}"
I created a small File Browser Control:
<UserControl x:Class="Test.UserControls.FileBrowserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="44" d:DesignWidth="461" Name="Control">
<Grid Margin="3">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<TextBox Margin="3" Text="{Binding SelectedFile}" IsReadOnly="True" TextWrapping="Wrap" />
<Button HorizontalAlignment="Right" Margin="3" Width="100" Content="Browse" Grid.Column="1" Command="{Binding BrowseCommand}" />
</Grid>
</UserControl>
With the following code behind:
public partial class FileBrowserControl : UserControl
{
public ICommand BrowseCommand { get; set; }
//The dependency property
public static DependencyProperty SelectedFileProperty = DependencyProperty.Register("SelectedFile",
typeof(string),typeof(FileBrowserControl), new PropertyMetadata(String.Empty));
public string SelectedFile { get{ return (string)GetValue(SelectedFileProperty);} set{ SetValue(SelectedFileProperty, value);}}
//For my first test, this is a static string
public string Filter { get; set; }
public FileBrowserControl()
{
InitializeComponent();
BrowseCommand = new RelayCommand(Browse);
Control.DataContext = this;
}
private void Browse()
{
SaveFileDialog dialog = new SaveFileDialog();
if (Filter != null)
{
dialog.Filter = Filter;
}
if (dialog.ShowDialog() == true)
{
SelectedFile = dialog.FileName;
}
}
}
And I use it like this:
<userControls:FileBrowserControl SelectedFile="{Binding SelectedFile}" Filter="XSLT File (*.xsl)|*.xsl|All Files (*.*)|*.*"/>
(SelectedFile is Property of the ViewModel of the usercontrol using this control)
Currently the issue is that when I click on Browse, the textbox in the usercontrol is correctly updating, but the SelectedFile property of the viewmodel parent control is not set(no call to the set property).
If I set the Mode of the binding to TwoWay, I got this exception:
An unhandled exception of type 'System.StackOverflowException' occurred in Unknown Module.
So what did I do wrong?
The problem is that you set your UserControl's DataContext to itself in its constructor:
DataContext = this;
You should not do that, because it breaks any DataContext based Bindings, i.e. to a view model instance that is provided by property value inheritance of the DataContext property
Instead you would change the binding in the UserControl's XAML like this:
<TextBox Text="{Binding SelectedFile,
RelativeSource={RelativeSource AncestorType=UserControl}}" />
Now, when you use your UserControl and write a binding like
<userControls:FileBrowserControl SelectedFile="{Binding SelectedFile}" />
the SelectedFile property gets bound to a SelectedFile property in your view model, which should be in the DataContext inherited from a parent control.
Do not ever set DataContext of UserControl inside usercontrol:
THIS IS WRONG:
this.DataContext = someDataContext;
because if somebody will use your usercontrol, its common practice to set its datacontext and it is in conflict with what you have set previously
<my:SomeUserControls DataContext="{Binding SomeDataContext}" />
Which one will be used? Well, it depends...
The same applies to Name property. you should not set name to UserControl like this:
<UserControl x:Class="WpfApplication1.SomeUserControl" Name="MyUserControl1" />
because it is in conflict with
<my:SomeUserControls Name="SomeOtherName" />
SOLUTION:
In your control, just use RelativeSource Mode=FindAncestor:
<TextBox Text="{Binding SelectedFile, RelativeSource={RelativeSource AncestorType="userControls:FileBrowserControl"}" />
To your question on how are all those third party controls done: They use TemplateBinding. But TemplateBinding can be used only in ControlTemplate. http://www.codeproject.com/Tips/599954/WPF-TemplateBinding-with-ControlTemplate
In usercontrol the xaml represents Content of UserControl, not ControlTemplate/
Using this:
<userControls:FileBrowserControl SelectedFile="{Binding SelectedFile}" ...
The FileBrowserControl's DataContext has already been set to itself, therefore you are effectively asking to bind to the SelectedFile where the DataContext is the FileBrowserControl, not the parent ViewModel.
Give your View a name and use an ElementName binding instead.
SelectedFile="{Binding DataContext.SelectedFile, ElementName=element}"
I can not get the binding of a text property for a DataTemplate in MVVM design pattern.
To show the problem I expose below a simplification of my problem, where I bind two different view properties to the same model property (aka AnObject.Text).
My code in MainWindow.xaml is:
...
<Button Grid.Row="0" Content="{Binding ButtonText}" />
...
<ScrollViewer Grid.Row="1" VerticalScrollBarVisibility="Auto">
<ItemsControl ItemsSource="{Binding MyItems}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<DockPanel>
<Label Content="aaaaa" />
<TextBlock Text="{Binding ItemText}" />
</DockPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
...
My code behind in MainWindow.xaml.cs (which sets the same DataContext for Button and every item in <ItemsControl ItemsSource>):
public MainWindow()
{
InitializeComponent();
DataContext = new MainWindowViewModel();
}
My code in MainWindowViewModel.cs is:
...
public ObservableCollection<object> MyItems => MyConverter.GetCollection(MyData.List);
public string ItemText => "dddd"; // this DOES works
public string ItemText => AnObject.Text; // this does NOT work
...
public string ButtonText => AnObject.Text; // this DOES works (note, same object property!)
...
Any idea why my binding inside the DataTemplate does not work?
Thanks in advance!
There are various things to understand here:
Button control will have the DataContext set to MainWindowViewModel instance. This is the reason why ButtonText variable value is getting reflected in Button control text.
For ItemsControl the DataContext is the the same as for the Button, i.e. the MainWindowViewModel instance.
Each item in the ItemsControl ItemsSource acts as a DataContext for the elements in the ItemTemplate, i.e. the DockPanel and its child elements. This is managed automatically by the framework. So essentially you will need a public property named ItemText in the class which will act as a DataContext for Dockpanel.
In your case the ItemText property is not the part of the objects which are in list.
I have a UserControl which contains a listbox and few buttons.
<UserControl x:Class="ItemControls.ListBoxControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
<Grid>
<ListBox:ExtendedListBox SelectionMode="Single" ItemsSource="{Binding LBItems}" Height="184">
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<Button Command="RemoveCommand"/>
</Grid>
</UserControl>
And the code behind:
public static readonly DependencyProperty RemoveCommandProperty =
DependencyProperty.Register("RemoveCommand", typeof(ICommand), typeof(ListBoxControl), null);
public ICommand RemoveCommand
{
get { return (ICommand)GetValue(RemoveCommandProperty); }
set { SetValue(RemoveCommandProperty, value); }
}
public static readonly DependencyProperty LBItemsProperty =
DependencyProperty.Register("LBItems", typeof(IEnumerable), typeof(ListBoxControl), null);
public IEnumerable LBItems
{
get { return (IEnumerable)GetValue(LBItemsProperty); }
set { SetValue(LBItemsProperty, value); }
}
I'm using this control in the view like this:
<ItemControls:ListBoxControl Height="240" Width="350" LBItems="{Binding Items, Converter={StaticResource ItemsConverter}, Mode=TwoWay}" RemoveCommand="{Binding RemoveCommand}"/>
The command works fine, though the listbox binding doesn't. My question is - WHY?
The ListBox in your UserControl isn't correctly binding to LBItems. The DataContext of the ListBox is not your control so it's trying to bind LBItems directly from your ViewModel.
In your UserControl declaration add DataContext="{Binding RelativeSource={RelativeSource Self}}". That should correctly set your DataContext to the UserControl and allow you binding to correctly locate the LBItems property.
Edit
Your comment reminded me. You need to set the DataContext of your Grid to be your UserControl. The simplest way to do this is to name the Grid i.e. <Grid x:Name="LayoutRoot"> and then in the constructor for your UserControl LayoutRoot.DataContext = this;
If you set the DataContext of the UserControl you break the bindings from your VM, but if you set them on the Grid the top bindings still work and all controls inside the UserControl can correctly bind to the UserControl.
What is the proper way to implement Custom Properties in Silverlight UserControls?
Every "Page" in Silverlight is technically a UserControl (they are derived from the UserControl class). When I say UserControl here, I mean a Custom UserControl that will be used inside many different pages in many different scenarios (similar to an ASP.NET UserControl).
I would like the Custom UserControl to support Binding and not rely on the Name of the Property it is binding to, to always be the same. Instead, I would like the UserControl itself to have a property that the Controls inside the UserControl bind to, and the ViewModels outside the UserControl also bind to. (please see the example below)
Binding within the UserControl works, Binding within the MainPage works, The Binding I set up between the MainPage and the UserControl does not work. Specifically this line:
<myUserControls:MyCustomUserControl x:Name="MyCustomControl2"
SelectedText="{Binding MainPageSelectedText, Mode=TwoWay}"
Width="200" Height="50" />
example output:
MainPage.xaml
<UserControl x:Class="SilverlightCustomUserControl.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:myUserControls="clr-namespace:SilverlightCustomUserControl"
mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480"
DataContext="{Binding RelativeSource={RelativeSource Self}}">
<Canvas x:Name="LayoutRoot">
<StackPanel Orientation="Vertical">
<TextBlock Text="UserControl Binding:" Width="200"></TextBlock>
<myUserControls:MyCustomUserControl x:Name="MyCustomControl2" SelectedText="{Binding MainPageSelectedText, Mode=TwoWay}" Width="200" Height="50" />
<TextBlock Text="MainPage Binding:" Width="200"></TextBlock>
<TextBox Text="{Binding MainPageSelectedText, Mode=TwoWay}" Width="200"></TextBox>
<Border BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding MainPageSelectedText}" Width="200" Height="24"></TextBlock>
</Border>
</StackPanel>
</Canvas>
</UserControl>
MainPage.xaml.cs
namespace SilverlightCustomUserControl
{
public partial class MainPage : UserControl, INotifyPropertyChanged
{
//NOTE: would probably be in a ViewModel
public string MainPageSelectedText
{
get { return _MainPageSelectedText; }
set
{
string myValue = value ?? String.Empty;
if (_MainPageSelectedText != myValue)
{
_MainPageSelectedText = value;
OnPropertyChanged("MainPageSelectedText");
}
}
}
private string _MainPageSelectedText;
public MainPage()
{
InitializeComponent();
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string name)
{
PropertyChangedEventHandler ph = this.PropertyChanged;
if (ph != null)
ph(this, new PropertyChangedEventArgs(name));
}
#endregion
}
}
MyCustomUserControl.xaml
<UserControl
x:Class="SilverlightCustomUserControl.MyCustomUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
DataContext="{Binding RelativeSource={RelativeSource Self}}">
<Grid>
<StackPanel>
<TextBox Text="{Binding SelectedText, Mode=TwoWay}" />
<Border BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding SelectedText}" Height="24"></TextBlock>
</Border>
</StackPanel>
</Grid>
</UserControl>
MyCustomUserControl.xaml.cs
namespace SilverlightCustomUserControl
{
public partial class MyCustomUserControl : UserControl
{
public string SelectedText
{
get { return (string)GetValue(SelectedTextProperty); }
set { SetValue(SelectedTextProperty, value); }
}
public static readonly DependencyProperty SelectedTextProperty =
DependencyProperty.Register("SelectedText", typeof(string), typeof(MyCustomUserControl), new PropertyMetadata("", SelectedText_PropertyChangedCallback));
public MyCustomUserControl()
{
InitializeComponent();
}
private static void SelectedText_PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
//empty
}
}
}
References (how I got this far):
use DependencyPropertys:
http://geekswithblogs.net/thibbard/archive/2008/04/22/wpf-custom-control-dependency-property-gotcha.aspx
use DependencyPropertys, add x:Name to your UserControl - add Binding with ElementName, set Custom property again in the PropertyChangedCallback method:
Setting Custom Properties in UserControl via DataBinding
don't use custom properties, rely on underlying datacontext names (I do not like this solution):
wpf trouble using dependency properties in a UserControl
I understand it as the reason your control is not receiving the new value from the maim page is that you are setting the DataContext of the control. If you hadn't then the control's DataContext will be inherited from its parent, the main page in this case.
To get this to work I removed you control's DataContext setting, added an x:Name to each control and set the binding in the constructor of the control using the [name].SetBinding method.
I did the binding in the ctor as I couldn't figure out a way of setting the Source property of the declarative binding in the xaml to Self. i.e. {Binding SelectedText, Mode=TwoWay, Source=[Self here some how]}. I did try using RelativeSource={RelativeSource Self} with no joy.
NOTE: All this is SL3.
The Issue was the UserControl was throwing a DataBinding error (visible in the Output window while debugging)
Because The UserControl's DataContext was set to "Self" in its own xaml, it was looking for the MainPageSelectedText within its own context (it was not looking for the MainPageSelectedText within the "MainPage" which is where you might think it would look, because when you are physically writing/looking at the code that is what is in "context")
I was able to get this "working" by setting the Binding in the code behind. Setting the binding in the code behind is the only way to set the UserControl itself as the "Source" of the binding. But this only works if the Binding is TwoWay. OneWay binding will break this code. A better solution altogether would be to create a Silverlight Control, not a UserControl.
See Also:
http://social.msdn.microsoft.com/Forums/en-US/silverlightcontrols/thread/052a2b67-20fc-4f6a-84db-07c85ceb3303
http://msdn.microsoft.com/en-us/library/cc278064%28VS.95%29.aspx
MyCustomUserControl.xaml
<UserControl
x:Class="SilverlightCustomUserControl.MyCustomUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
<Grid>
<StackPanel>
<TextBox x:Name="UserControlTextBox" />
<Border BorderBrush="Black" BorderThickness="1">
<TextBlock x:Name="UserControlTextBlock" Height="24"></TextBlock>
</Border>
</StackPanel>
</Grid>
</UserControl>
MyCustomUserControl.xaml.cs
namespace SilverlightCustomUserControl
{
public partial class MyCustomUserControl : UserControl
{
public string SelectedText
{
get { return (string)GetValue(SelectedTextProperty); }
set { SetValue(SelectedTextProperty, value); }
}
public static readonly DependencyProperty SelectedTextProperty =
DependencyProperty.Register("SelectedText", typeof(string), typeof(MyCustomUserControl), new PropertyMetadata("", SelectedText_PropertyChangedCallback));
public MyCustomUserControl()
{
InitializeComponent();
//SEE HERE
UserControlTextBox.SetBinding(TextBox.TextProperty, new Binding() { Source = this, Path = new PropertyPath("SelectedText"), Mode = BindingMode.TwoWay });
UserControlTextBlock.SetBinding(TextBlock.TextProperty, new Binding() { Source = this, Path = new PropertyPath("SelectedText") });
//SEE HERE
}
private static void SelectedText_PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
//empty
}
}
}
Instead of binding data context to self, you can set the binding in xaml by adding an x:Name for the user control and then binding in the user control xaml follows:
<UserControl
x:Class="SilverlightCustomUserControl.MyCustomUserControl"
x:Name="myUserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
<Grid>
<StackPanel>
<TextBox Text="{Binding SelectedText, ElementName=myUserContol, Mode=TwoWay}" />
<Border BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding SelectedText,ElementName=myUserControl}" Height="24"></TextBlock>
</Border>
</StackPanel>
</Grid>
</UserControl>