Silverlight UserControl Custom Property Binding

Question

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

Answer 1

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

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
  }

 }
}