Bind to property of a control in another view - wpf

Question

I have set up in a view the height of a control using dockpanels and alignments.
I want to use the computed size of this control as an input for another control in another view.
MainWindow
<StackPanel>
<local:View1 />
<local:View2 />
</StackPanel>
View1
<DockPanel>
...
<Button x:Name="myButton" />
...
</DockPanel>
View2 (where I want to bind the button's height to the first view)
<Button Height="{Binding Path=Button.Height, RelativeSource={RelativeSource AncestorType={x:Type local:View1}}}" />
But it does not work...
I am looking if possible for a xaml-only solution with binding...

Answer 1

You may want to try using dependency properties in order to achieve this. Here is a sample based on your case:
View1:
<DockPanel>
<Button x:Name="myButton" Content="Button in view1" FontSize="32"/>
</DockPanel>
View1 codebehind. Notice that we handle loaded event in order to get the actual height of the button and to assign its value to the DependencyProperty we created:
public static readonly DependencyProperty ButtonHeightProperty = DependencyProperty.Register(
"ButtonHeight", typeof (double), typeof (View1), new PropertyMetadata(default(double)));
public double ButtonHeight
{
get { return (double) GetValue(ButtonHeightProperty); }
set { SetValue(ButtonHeightProperty, value); }
}
public View1()
{
InitializeComponent();
}
private void View1_OnLoaded(object sender, RoutedEventArgs e)
{
ButtonHeight = myButton.ActualHeight;
}
Then in view2 we bind the button height to another dependency property in that user control:
And in view2 codebehind:
public static readonly DependencyProperty ButtonHeightProperty = DependencyProperty.Register(
"ButtonHeight", typeof (double), typeof (View2), new PropertyMetadata(default(double)));
public double ButtonHeight
{
get { return (double) GetValue(ButtonHeightProperty); }
set { SetValue(ButtonHeightProperty, value); }
}
public View2()
{
InitializeComponent();
}
Finally the mainWindow xaml looks like this:
<StackPanel>
<local:View1 x:Name="View1"/>
<local:View2 ButtonHeight="{Binding ElementName=View1,Path=ButtonHeight}"/>
</StackPanel>
And the output:
Hope this helps