Silverlight: Wrapping a non-DependencyProperty in a DependencyProperty

Question

Hi,

I want to be able to add a Binding to some properties of a DataGridTextColumn (i.e. Width, Sorting order, etc.), however it seems that those properties are not DependencyPropertys, so they can't be bound to. Another answer suggested subclassing DataGridTextColumn to expose those properties as DependencyPropertys, however I can't seem to find any info on how to do this.

Thanks, Robert

Answer 1

Try this:

public class BindableGridColumn : DataGridTextColumn
    {
        public DataGridLength BindableWidth
        {
            get { return Width; }
            set { 
                  SetValue(BindableWidthProperty, value);
                  Width = value; 
                }
        }

        // Using a DependencyProperty as the backing store for BindableWidth.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty BindableWidthProperty =
            DependencyProperty.Register("BindableWidth", typeof(DataGridLength), typeof(BindableGridColumn), new PropertyMetadata(DataGridLength.Auto));
    }

Answer 2

In Silverlight, only subclasses of FrameworkElement (not DependencyObject) can have DependencyPropertys. So it's impossible to bind directly to a DataGridColumn's properties.