How to: Override Metadata for a Dependency Property

Question

how to override default dependency property metadata. for example ;Text property for textbox. i use this code

           class UCTextBox : TextBox
       {
           public UCTextBox()
        {
       var defaultMetadata = TextBox.TextProperty.GetMetadata(typeof(TextBox));

       TextBox.TextProperty.OverrideMetadata(typeof(UCTextBox),
     new          FrameworkPropertyMetadata(string.Empty,
        FrameworkPropertyMetadataOptions.Journal | 
     FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
        defaultMetadata.PropertyChangedCallback,
        new CoerceValueCallback(CoerceText)
        )); 
}

    private static object CoerceText(DependencyObject d, object value)
     {
     return   value.ToString().Replace(",","");           
    }

but this In both runs(get,set)

No one can help me!!!:(((

possible duplicate of [How can I change the default value of an inherited dependency property?](http://stackoverflow.com/questions/5653364/how-can-i-change-the-default-value-of-an-inherited-dependency-property) — Jeff Mercado, Oct 01 '11 at 06:02

score 23 · Answer 1 · answered Oct 01 '11 at 06:25

23

Here is an example of a class derived from TextBox overriding the metadata for the Text property:

using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;

public class MyTextBox : TextBox
{
    static MyTextBox()
    {
        TextBox.TextProperty.OverrideMetadata(typeof(MyTextBox),
            new FrameworkPropertyMetadata(string.Empty,
                FrameworkPropertyMetadataOptions.BindsTwoWayByDefault |
                FrameworkPropertyMetadataOptions.Journal,
                null, /* property changed callback */
                null, /* coerce value callback */
                true, /* is animation prohibited */
                UpdateSourceTrigger.LostFocus));
    }
}

Notice that the override is place in the static constructor, not the ordinary constructor.

answered Oct 01 '11 at 06:25

Rick Sladkey

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thanks, i want this code in wpf. [get {return text.replace();} se{text=value;}] – ar.gorgin Oct 01 '11 at 07:08
This is WPF code. That's the way to do custom controls (i.e: overriding metadata in a static constructor of a class that derives from UIElement). – Louis Kottmann Oct 01 '11 at 09:49
how do i change the value when get Text property?! – ar.gorgin Oct 01 '11 at 10:21

How to: Override Metadata for a Dependency Property

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