How do I specify a control as a property in my user control in WPF?

Question

My XAML:

<TextBox x:Name="myTextBox" .../>
<MyExtender TargetTextBox=? .../>

My C#:

MyExtender : UserControl
{
    public TargetTextBox { get; set; }
}

How do I set the TargetTextBox property in XAML?

Answer 1

You should be able to do:

<TextBox Name="tb">Something</TextBox>
<my:MyExtender TargetTextBox="{Binding ElementName=tb}" />

but this requires TargetTextBox to be a DependencyProperty. Change MyExtender.xaml.cs to:

 public partial class MyExtender : System.Windows.Controls.UserControl
{
    public MyExtender()
    {
        InitializeComponent();
    }
    public static readonly DependencyProperty TargetTextBoxPropery = 
        DependencyProperty.Register("TargetTextBox", typeof(TextBox), typeof(MyExtender));

    public TextBox TargetTextBox
    {
        get { return (TextBox)GetValue(TargetTextBoxPropery); }
        set { SetValue(TargetTextBoxPropery, value); }
    }

}

And you should be set.