silverlight 文件下载若干方法

方法一：WebService

前台代码：

  
    

   
      
   
     <
   
     DataTemplate
   
     >
   
     
 
   
     <
   
     Button 
   
     Content
   
     ="下载"
   
      Height
   
     ="23"
   
      Name
   
     ="button3"
   
      Tag
   
     ="
   
     {Binding Udocname}
   
     "
   
      Width
   
     ="60"
   
      Click
   
     ="button3_Click"
   
      
   
     />
   
     

   
     </
   
     DataTemplate
   
     >
   
     
 
  
    

后台代码：

  
    

   
      
   
     private
   
      
   
     void
   
      button3_Click(
   
     object
   
      sender, RoutedEventArgs e)
 {
  
    
  
    

   
      Button b 
   
     =
   
      sender 
   
     as
   
      Button;
 
   
     //
   
     实例化button

 
   
     //
   
     _file 要下载的文件路径
 
   
     //
   
     string _file = "
   
     http://localhost
   
     :8080/EHRWCF/upload/2.rar"; 
   
     //
   
     这里改成你网站里的文件路径
   
     

   
      
   
     string
   
      _file 
   
     =
   
      
   
     "
   
     http://192.168.1.102:8080/EHRWCF/upload/
   
     "
   
      
   
     +
   
      b.Tag.ToString();
 SaveFileDialog sf 
   
     =
   
      
   
     new
   
      SaveFileDialog();
 sf.DefaultExt 
   
     =
   
      
   
     "
   
     rar
   
     "
   
     ;
 sf.Filter 
   
     =
   
      
   
     "
   
     rar压缩文件 (*.rar)|*.rar|zip压缩文件 (*.zip)|*.zip|所有文件 (*.*)|*.*
   
     "
   
     ;
 sf.FilterIndex 
   
     =
   
      
   
     1
   
     ;
 
   
     if
   
      (sf.ShowDialog() 
   
     !=
   
      
   
     true
   
     ) 
   
     return
   
     ;
 Stream clientStream 
   
     =
   
      sf.OpenFile();
 Uri _uri 
   
     =
   
      
   
     new
   
      Uri(_file, UriKind.Absolute);
 WebClient client 
   
     =
   
      
   
     new
   
      WebClient();

 
   
     if
   
      (client.IsBusy)
 {
 client.CancelAsync();
 }
 client.OpenReadCompleted 
   
     +=
   
      
   
     new
   
      OpenReadCompletedEventHandler(client_OpenReadCompleted);

 client.OpenReadAsync(_uri, clientStream);
 
 }
 
   
     #region
   
      异步文件下载
   
     
 
   
     void
   
      client_OpenReadCompleted(
   
     object
   
      sender, OpenReadCompletedEventArgs e)
 {
 
   
     if
   
      (e.Error 
   
     !=
   
      
   
     null
   
     )
 {
 
   
     //
   
     txtinfo.Text += e.Error.Message;
   
     

   
      MessageBox.Show(e.Error.ToString());
 
   
     //
   
     MessageBox.Show("下载文件时出错，可能是文件已经不存在！");
   
     

   
      
   
     return
   
     ;
 }
 
   
     if
   
      (e.Cancelled 
   
     !=
   
      
   
     true
   
     )
 {
 Stream clientStream 
   
     =
   
      e.UserState 
   
     as
   
      Stream;
 Stream serverStream 
   
     =
   
      (Stream)e.Result;
 
   
     byte
   
     [] buffer 
   
     =
   
      
   
     new
   
      
   
     byte
   
     [serverStream.Length];
 serverStream.Read(buffer, 
   
     0
   
     , buffer.Length);
 clientStream.Write(buffer, 
   
     0
   
     , buffer.Length);
 clientStream.Close();
 serverStream.Close();
 }
 }
 
   
     #endregion
  
    

方法2：使用下载控件类似于asp.net中的<a href="url"></a>方法

前台代码：

  
    

   
     //引用命名空间
xmlns:localConv="clr-namespace:KX_EHR.Class"

   
     <
   
     UserControl.Resources
   
     >
   
     
 
   
     <
   
     localConv:ConvtoAddStr 
   
     x:Key
   
     ="ConvtoAddString"
   
     />
   
     
 
   
     </
   
     UserControl.Resources
   
     >
   
     

//datagrid中

   
     <
   
     DataTemplate
   
     >
   
     
 
   
     <
   
     HyperlinkButton 
   
     Content
   
     ="下载"
   
      NavigateUri
   
     ="
   
     {Binding Udocname,Converter={StaticResource ConvtoAddString}}
   
     "
   
     ></
   
     HyperlinkButton
   
     >
   
     

   
     </
   
     DataTemplate
   
     >
  
    

 后台类型转化器：

  
    

   
      ///
   
      
   
     <summary>
   
     
 
   
     ///
   
      把代码转化成指定的类容
 
   
     ///
   
      
   
     </summary>
   
     
 
   
     ///
   
      
   
     <param name="value"></param>
   
     
 
   
     ///
   
      
   
     <param name="targetType"></param>
   
     
 
   
     ///
   
      
   
     <param name="parameter"></param>
   
     
 
   
     ///
   
      
   
     <param name="culture"></param>
   
     
 
   
     ///
   
      
   
     <returns></returns>
   
     

   
      
   
     public
   
      
   
     class
   
      ConvtoAddStr : IValueConverter
 {
 
   
     public
   
      
   
     object
   
      Convert(
   
     object
   
      value, Type targetType, 
   
     object
   
      parameter, System.Globalization.CultureInfo culture)
 {
 
   
     if
   
      (
   
     !
   
     value.ToString().Contains(
   
     @"
   
     http://192.168.1.102:8080/EHRWCF/upload/
   
     "
   
     ))
 {
 
   
     return
   
      
   
     @"
   
     http://192.168.1.102:8080/EHRWCF/upload/
   
     "
   
      
   
     +
   
      value;
 }
 
   
     else
   
     
 
   
     return
   
      value;
 }

 
   
     public
   
      
   
     object
   
      ConvertBack(
   
     object
   
      value, Type targetType, 
   
     object
   
      parameter, System.Globalization.CultureInfo culture)
 {
 
   
     if
   
      (value.ToString().Contains(
   
     @"
   
     http://192.168.1.102:8080/EHRWCF/upload/
   
     "
   
     ))
 {
 
   
     return
   
      value.ToString().Replace(
   
     @"
   
     http://192.168.1.102:8080/EHRWCF/upload/
   
     "
   
     , 
   
     ""
   
     );
 }
 
   
     else
   
     
 
   
     return
   
      value;
 } 
 }