Windows Phone 7 MVVM模式通讯方式之实现Attached Behavior-优快云博客

MVVM模式的View与ViewModel的三大通讯方式：Binding Data（实现数据的传递）、Command（实现操作的调用）和Attached
Behavior（实现控件加载过程中的操作）。

下面通过一个实例实现MVVM模式的Attached Behavior通讯，Attached Behavior与Command的区别就是，Attached Behavior在控件的加载过程中完成它的任务。

下面看一下实例的运行效果：

（1）MainPage.xaml页面代码，View层

     
      <
      phone:PhoneApplicationPage 
    
      x:Class
      ="AttachedBehaviorDemo.MainPage"
      
    xmlns
      ="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      
    xmlns:x
      ="http://schemas.microsoft.com/winfx/2006/xaml"
      
    xmlns:phone
      ="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
      
    xmlns:shell
      ="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
      
    xmlns:d
      ="http://schemas.microsoft.com/expression/blend/2008"
      
    xmlns:mc
      ="http://schemas.openxmlformats.org/markup-compatibility/2006"
      
    xmlns:local
      ="clr-namespace:AttachedBehaviorDemo"
       
    mc:Ignorable
      ="d"
       d:DesignWidth
      ="480"
       d:DesignHeight
      ="768"
      
    FontFamily
      ="
      {StaticResource PhoneFontFamilyNormal}
      "
      
    FontSize
      ="
      {StaticResource PhoneFontSizeNormal}
      "
      
    Foreground
      ="
      {StaticResource PhoneForegroundBrush}
      "
      
    SupportedOrientations
      ="Portrait"
       Orientation
      ="Portrait"
      
    shell:SystemTray.IsVisible
      ="True"
      >
      

    
      <
      Grid 
      x:Name
      ="LayoutRoot"
       Background
      ="Transparent"
      >
      
        
      <
      Grid.RowDefinitions
      >
      
            
      <
      RowDefinition 
      Height
      ="Auto"
      />
      
            
      <
      RowDefinition 
      Height
      ="*"
      />
      
        
      </
      Grid.RowDefinitions
      >
      

        
      <
      StackPanel 
      x:Name
      ="TitlePanel"
       Grid.Row
      ="0"
       Margin
      ="12,17,0,28"
      >
      
            
      <
      TextBlock 
      x:Name
      ="ApplicationTitle"
       Text
      ="MY APPLICATION"
       Style
      ="
      {StaticResource PhoneTextNormalStyle}
      "
      />
      
            
      <
      TextBlock 
      x:Name
      ="PageTitle"
       Text
      ="AttachedBehavior"
       Margin
      ="9,-7,0,0"
       Style
      ="
      {StaticResource PhoneTextTitle1Style}
      "
      />
      
        
      </
      StackPanel
      >
      

        
      <
      Grid 
      x:Name
      ="ContentPanel"
       Grid.Row
      ="1"
       Margin
      ="12,0,12,0"
      >
      
            
      <
      TextBlock 
      FontSize
      ="50"
       Text
      ="金色 Gold"
       local:Behavior.Brush
      ="Gold"
       Margin
      ="0,6,0,504"
       
      />
      
            
      <
      TextBlock 
      FontSize
      ="50"
        Text
      ="绿色 Green"
       local:Behavior.Brush
      ="Green"
       Margin
      ="0,94,0,416"
       
      />
      
            
      <
      TextBlock 
      FontSize
      ="50"
        Text
      ="蓝色 Blue"
       local:Behavior.Brush
      ="Blue"
       Margin
      ="0,184,0,339"
       
      />
      
            
      <
      TextBlock 
      FontSize
      ="50"
        Text
      ="橙色 Orange"
       local:Behavior.Brush
      ="Orange"
       Margin
      ="-3,274,3,243"
       
      />
      
            
      <
      TextBlock 
      FontSize
      ="50"
        Text
      ="紫色 Purple"
       local:Behavior.Brush
      ="Purple"
       Margin
      ="0,386,0,133"
       
      />
      
            
      <
      TextBlock 
      FontSize
      ="50"
        Text
      ="橄榄色 Olive"
       local:Behavior.Brush
      ="Olive"
       Margin
      ="0,497,0,0"
       Height
      ="110"
       VerticalAlignment
      ="Top"
       
      />
      
        
      </
      Grid
      >
      
    
      </
      Grid
      >
      
    

      </
      phone:PhoneApplicationPage
      >

（2） Behavior.cs 类代码，处理附加的属性和事件。

     
      using
       System.Windows;

      using
       System.Windows.Controls;

      using
       System.Windows.Input;

      using
       System.Windows.Media;


      namespace
       AttachedBehaviorDemo
{
    
      static
       
      public
       
      class
       Behavior
    {
        
      //
      注册一个附加属性BrushProperty，在XAML中名字为Brush，是Brush类型，在Hover类中，PropertyMetadata初始化元数据
      

              
      public
       
      static
       
      readonly
       DependencyProperty BrushProperty 
      =
       DependencyProperty.RegisterAttached(
            
      "
      Brush
      "
      ,
            
      typeof
      (Brush),
            
      typeof
      (Behavior),
            
      new
        PropertyMetadata (
      null
      , 
      new
       PropertyChangedCallback(OnHoverBrushChanged)));

        
      ///
       
      <summary>
      
        
      ///
       获取Brush的属性值
        
      ///
       
      </summary>
      
        
      ///
       
      <param name="obj"></param>
      
        
      ///
       
      <returns></returns>
      

              
      public
       
      static
       Brush GetBrush(DependencyObject obj)
        {
            
      return
       (Brush)obj.GetValue(BrushProperty);
        }
        
      ///
       
      <summary>
      
        
      ///
       设置属性的值
        
      ///
       
      </summary>
      
        
      ///
       
      <param name="obj"></param>
      
        
      ///
       
      <param name="value"></param>
      

              
      public
       
      static
       
      void
       SetBrush(DependencyObject obj, Brush value)
        {
            obj.SetValue(BrushProperty, value);
        }
        
      ///
       
      <summary>
      
        
      ///
       属性初始化
        
      ///
       
      </summary>
      
        
      ///
       
      <param name="obj"></param>
      
        
      ///
       
      <param name="args"></param>
      

              
      private
       
      static
       
      void
       OnHoverBrushChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
        {
            
      //
      获取属性所在的TextBlock控件
      

                  TextBlock control 
      =
       obj 
      as
       TextBlock;
            
      //
      注册控件的事件
      

                  
      if
       (control 
      !=
       
      null
      )
            {
                
      //
      注册鼠标进入事件
      

                      control.MouseEnter 
      +=
       
      new
       MouseEventHandler(OnControlEnter);
                
      //
      注册鼠标离开事件
      

                      control.MouseLeave 
      +=
       
      new
       MouseEventHandler(OnControlLeave);
            }

        }
        
      ///
       
      <summary>
      
        
      ///
       鼠标进入事件
        
      ///
       
      </summary>
      
        
      ///
       
      <param name="sender"></param>
      
        
      ///
       
      <param name="e"></param>
      

              
      static
       
      void
       OnControlEnter(
      object
       sender, MouseEventArgs e)
        {
            
      //
      获取当前的TextBlock控件
      

                  TextBlock control 
      =
       (TextBlock)e.OriginalSource; 
            
      //
      设置控件的前景颜色为红色
      

                  control.Foreground 
      =
       
      new
       SolidColorBrush(Colors.Red);
        }

        
      ///
       
      <summary>
      
        
      ///
       鼠标离开事件
        
      ///
       
      </summary>
      
        
      ///
       
      <param name="sender"></param>
      
        
      ///
       
      <param name="e"></param>
      

              
      static
       
      void
       OnControlLeave(
      object
       sender, MouseEventArgs e)
        {
            
      //
      获取当前的TextBlock控件
      

                  TextBlock control 
      =
       (TextBlock)e.OriginalSource;
            
      //
      设置控件的前景颜色为当前控件的Brush属性的值
      

                  control.Foreground 
      =
       GetBrush(control);
        } 

    }
}