How to get object in UserControl from another Control

Question

I have MainWindow , MenuControl , EditorControl in my WPF App.

When I click the "Get Height" Button in MenuControl , I want to get the StackPanel 's Height in EditorControl .

How can I get the StackPanel object in EditorControl ?

MenuControl.xaml:

<Button Content="Get Height" Click="GetStackPanelHeight_Click"/>

EditorControl.xaml:

<StackPanel x:Name="xxxx">
    <Label Context="test">
</StackPanel>

MenuControl.xaml.cs:

public void GetStackPanelHeight_Click(object sender, RoutedEventArgs e)
{
    var tmp = xxxx.ActualHeight;       
}

can not access xxxx.AcutualHeight.

If I wrote below,tmp=0

var editorControl = new EditorControl();
var tmp = editorControl.xxxx.ActualHeight;

How can I do it?

Answer 1

One of the fastest solutions is: In EditorControl you can get the value of the StackPanel 's ActualHeight .

For example: Pass the StackPanel 's ActualHeight value into a DependencyProperty inside the EditorControl . When the Button in MenuControl is being pushed, read the value of that dependency property.

Answer 2

You can do it like this :

public class FirstUserControl
{
    public delegate void PropertyChangedHandler(object obj);
    public static event PropertyChangedHandler StackPanelHeightChanged = delegate { };
    public void GetStackPanelHeight_Click(object sender, RoutedEventArgs e)
    {
        //Example: here I fire the function in the second UC
        var tmp = xxxx.ActualHeight; 
        StackPanelHeightChanged(tmp);
    }
}

-

public class SecondUserControl
{
    public SecondUserControl()
    {
        FirstUserControl.StackPanelHeightChanged+= OnStackPanelHeightChanged;
    }

    public void OnStackPanelHeightChanged(object obj)
    {
        //here obj is the Height of the StackPanel
    }

    //....
}