silverlight依赖属性

1.一个实体类，需要实现“INotifyPropertyChanged”接口

 

代码

     public   class  student : INotifyPropertyChanged
    {
         string  name;

         public   string  Name
        {
             get  {  return  name; }
             set
            {
                name  =  value;

                 // 这里需要传递“Name”，而不是私有变量“name”
                NotifyPropertyChange( " Name " );       
            }
        }

         public   int  age {  get ;  set ; }

         #region  INotifyPropertyChanged 成员

         public   event  PropertyChangedEventHandler PropertyChanged;        // INotifyPropertyChanged接口委托
         private   void  NotifyPropertyChange( string  propertyName)
        {
             if  (PropertyChanged  !=   null )
            {
                 // 通知更新所有绑定了propertyName，属性的控件更新界面值
                PropertyChanged( this ,  new  PropertyChangedEventArgs(propertyName));
            }
        }

         #endregion
    }

 

 

2.在xaml中，设置控件的绑定更新方向： <sdk:Label Height="28" Content="{Binding Name,Mode=TwoWay}"

 

代码

     < Grid x:Name = " LayoutRoot " >
         < TextBox Height = " 23 "  HorizontalAlignment = " Left "  Margin = " 250,144,0,0 "  Name = " txtName "  VerticalAlignment = " Top "  Width = " 120 "   />
         < sdk:Label Height = " 23 "  Content = " 名称： "  HorizontalAlignment = " Left "  Margin = " 175,144,0,0 "  Name = " label1 "  VerticalAlignment = " Top "  Width = " 69 "   />
         < Button Content = " 确定 "  Height = " 23 "  HorizontalAlignment = " Left "  Margin = " 250,215,0,0 "  Name = " btnOK "  VerticalAlignment = " Top "  Width = " 75 "  Click = " btnOK_Click "   />
         < sdk:Label Height = " 28 "  Content = " {Binding Name,Mode=TwoWay} "  HorizontalAlignment = " Left "  Margin = " 175,103,0,0 "  Name = " labMessage "  VerticalAlignment = " Top "  Width = " 120 "   />
         < TextBox Height = " 23 "  HorizontalAlignment = " Left "  Margin = " 250,173,0,0 "  Name = " txtAge "  VerticalAlignment = " Top "  Width = " 120 "   />
         < sdk:Label Content = " 年龄： "  Height = " 23 "  HorizontalAlignment = " Left "  Margin = " 175,173,0,0 "  Name = " label3 "  VerticalAlignment = " Top "  Width = " 69 "   />
     </ Grid >

 

 

3.在cs代码中更新实体类的依赖属性

 

代码

     public   partial   class  Page1 : Page
    {
        student myStudent  =   new  student();

         public  Page1()
        {
            InitializeComponent();

            myStudent.Name  =   " 张三 " ;
            myStudent.age  =   20 ;

             this .DataContext  =  myStudent;
        }

         private   void  btnOK_Click( object  sender, RoutedEventArgs e)
        {
             // myStudent.Name更新的同时，也会自动更新labMessage.Content的值
            myStudent.Name  =  txtName.Text;
        }
    }