wpf 依赖强制回调

依赖属性的强制转换加回调，后期自己再改

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

namespace WpfWebBrowser
{
    /// <summary>
    /// Interaction logic for UriWindow.xaml
    /// </summary>
    public partial class UriWindow : Window
    {
        #region Uri


        FrameworkPropertyMetadata frmate = new FrameworkPropertyMetadata();
        
        /// <summary>
        /// Uri Dependency Property
        /// </summary>
        public static readonly DependencyProperty UriProperty =
            DependencyProperty.Register ("Uri", typeof (Uri), typeof (UriWindow),
                                         new FrameworkPropertyMetadata (new Uri("http://www.baidu.com"), PropertyChanged, CoerceValue), ValidateValue);
                                         
        /// <summary>
        /// Gets or sets the Uri property.  This dependency property
        /// indicates ....
        /// </summary>
        public Uri Uri
        {
            get { return (Uri) GetValue (UriProperty); }
            
            set
            {
               
                    SetValue (UriProperty, value);
               
            }
        }

        //属性改变
        static void PropertyChanged(DependencyObject dobj, DependencyPropertyChangedEventArgs e)
        {
            Debug.WriteLine(String.Format("PropertyChanged - 属性：{0} 新值：{1} 旧值：{2}", e.Property.Name, e.NewValue, e.OldValue));
        }

        //强制转换
        static object CoerceValue(DependencyObject dobj, object newValue)
        {
            Debug.WriteLine(String.Format("CoerceValue - {0}", newValue));

            if (newValue.ToString().StartsWith("http://"))
            {

                return newValue;
                
            }
            else
            {
                return new Uri(@"http://" + newValue.ToString());
            }
           // return newValue;
        }

        //验证
        static bool ValidateValue(object obj)
        {
            Debug.WriteLine(String.Format("ValidateValue - {0}", obj));
            return true;
        }
        
        #endregion
        
        public UriWindow()
        {
            InitializeComponent();
            frmate.CoerceValueCallback = new CoerceValueCallback(CoerceValue);
        }
        
        private void btn_Ok_Click (object sender, RoutedEventArgs e)
        {
            this.DialogResult = true;
            this.Close();
        }
        
        private void btn_Cancel_Click (object sender, RoutedEventArgs e)
        {
            this.Close();
        }
    }
}