Question

I want to display a child window that contains a combobox with several values coming from one of the child window’s property:

public partial class MyChildWindow : ChildWindow
{
    private ObservableCollection<MyClass> _collectionToBind = // initialize and add items to collection to make sure it s not empty...

    public ObservableCollection<MyClass> CollectionToBind
    {
        get { return _collectionToBind; }
        set { _collectionToBind = value; }
    }
}

How do I bind in XAML my combobox to the ComboBoxContent collection (both are in the same class)? I’ve tried several things such as:

 <ComboBox x:Name="linkCombo" ItemsSource="{Binding Path=CollectionToBind }" DisplayMemberPath="Description">

I’ve only been able to bind it in the code behind file and would like to learn the XAML way to do it.

Thank you!

Answer 1

In this case I would use ElementToElement binding like this:-

 <ComboBox x:Name="linkCombo" ItemsSource="{Binding Path=Parent.CollectionToBind, ElementName=LayoutRoot }" DisplayMemberPath="Description">

You give the Content element of the ChildWindow the x:Name of LayoutRoot (in the standard template for child window this is done for you). Hence you can bind to this named element and navigate to the containing ChildWindow by using its Parent property.

Using DataContext = this is tempting and works in simple scenarios but things can get awkward in more complex requirements when the DataContext has already been taken in this way.