在Silverlight中读取指定URL图片包数据

在silverlight开发，允许我们获取指定URL压缩包（zip）并读取其中的图片文件。而实现这个功能也非常简单。下面是运行效果图：

              

     
    
      首先，我们需要建立一个silverligth application ，名称为：DownLoadImg.
    
      下面就是相应的page.xaml代码:    

< Grid  x:Name ="LayoutRoot"  Background ="White" >
     Grid.RowDeFinitions
         RowDeFinition  Height ="250"   /> ="100" ="50" </ StackPanel  Grid.Row ="1" ListBox  ="ImageList" Button  ="Download"  Click ="StartDownLoad"  Content ="下载该图片" StackPanel

     ="0"             
         ScrollViewer  HorizontalScrollBarVisibility ="Auto"
             Image  ="ImgToFill"            
             Image ScrollViewer ="2" Canvas  Canvas.Top ="70" Rectangle   Name ="progressRectangle"  Height ="10"  Width ="0"  Fill ="AliceBlue" Rectangle  ="12"   Width ="202"  strokeThickness ="1"  stroke ="Black" TextBlock  ="progresstext"  Canvas.Left ="210"  Text ="0%"  FontSize Canvas
Grid

    接下来是 page.xaml.cs(相关内容见注释):

using  System;
 System.Collections.Generic;
 System.Linq;
 System.Net;
 System.Windows;
 System.Windows.Controls;
 System.Windows.Documents;
 System.Windows.Input;
 System.Windows.Media;
 System.Windows.Media.Animation;
 System.Windows.Shapes;

 System.IO;
 System.Windows.Resources;
 System.Windows.Media.Imaging;

namespace  DownLoadImg
{
     public partial class  Page : UserControl
    {
        WebClient wc  = new  WebClient();

          Page()
        {
            InitializeComponent();
             this .Loaded  +=  RoutedEventHandler(Page_Loaded);
        }

         // 加载图片列表数据          void  Page_Loaded( object  sender, RoutedEventArgs e)
        {
            ImageList.Items.Add( " 1.jpg " );
            ImageList.Items.Add( 2.png );
        }
         实例化下载设置  StartDownLoad(  o, EventArgs e)
        {
             初始化相应控件信息             ImgToFill.Visibility   Visibility.Collapsed;
            progressRectangle.Width    0 ;
            progresstext.Text  0% ;
             绑定下载过程中处理的事件             wc.OpenReadCompleted   OpenReadCompletedEventHandler(wc_OpenReadCompleted);
            wc.DownloadProgressChanged   DownloadProgressChangedEventHandler(wc_DownloadProgressChanged);
             开始异步读取压缩包中的文件信息             wc.OpenReadAsync(  Uri( img.zip , UriKind.Relative), ImageList.SelectedItem);
        }
        
          wc_OpenReadCompleted( ottom:0px; padding-left:0px; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; color:rgb(0, OpenReadCompletedEventArgs e)
        {
            实例化流资源信息，准备获取其中的图片数据             StreamResourceInfo sri   StreamResourceInfo(e.Result  as  Stream,  null );
             要读取的图片路径信息             String sURI   e.UserState   String;
             从流资源中获取指定的URL图片流信息             StreamResourceInfo imagestream   Application.GetResourceStream(sri,0)"> Uri(sURI, UriKind.Relative));
            BitmapImage imgsrc   BitmapImage();
             绑定该URL图片信息并进行显示             imgsrc.SetSource(imagestream.Stream);
            ImgToFill.source   imgsrc;
            ImgToFill.Visibility   Visibility.Visible;
            ImgToFill.Stretch   Stretch.Fill;
        }

          wc_DownloadProgressChanged( ottom:0px; padding-left:0px; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; color:rgb(0, DownloadProgressChangedEventArgs e)
        {
             下载过程中的进度显示             progresstext.Text   e.Progresspercentage.ToString()  + % ;
            progressRectangle.Width   ( double )e.Progresspercentage  * 2 ;         }     } }