Silverlight实现文件下载

首先在service层建一个Handler，内容如下：

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;

namespace test.Service
{
       public class WebClientDownHandler : IHttpHandler
    {
      

 
        public void ProcessRequest(HttpContext context)
        {

            String fileName = context.Request.QueryString["filename"]; //客户端保存的文件名
            String filePath = context.Server.MapPath("Pics/" + fileName); //路径

            //string fileName = "ChartImg.png.jpg";

            FileInfo fileInfo = new FileInfo(filePath);

            if (fileInfo.Exists)
            {

               

                byte[] buffer = new byte[102400];
                context.Response.Clear();

                FileStream iStream = File.OpenRead(filePath);
                long dataLengthToRead = iStream.Length; //获取下载的文件总大小

                context.Response.ContentType = "application/octet-stream";
                context.response.addheader("Content-disposition","attachment;  filename=" +
                                   HttpUtility.UrlEncode(fileName,System.Text.Encoding.UTF8));
                while (dataLengthToRead > 0 && context.Response.IsClientConnected)
                {
                    int lengthRead = iStream.Read(buffer,Convert.ToInt32(102400));//'读取的大小

                    context.Response.OutputStream.Write(buffer,lengthRead);
                    context.Response.Flush();
                    dataLengthToRead = dataLengthToRead - lengthRead;
                }
                context.Response.Close();
                context.Response.End();

            }

        
        }

 

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

}
假如我们的service的Pics目录下有一个文件test.doc

我们可以试试http://localhost/WebClientDownHandler.ashx?filename=test.doc 看看能不能访问下载文件

 

 

如果成功了，在Silverlight页面直接给HyperlinkButton指定NavigateUri为上述url就可以了，注意可能需要给HyperlinkButton加上TargetName="_self"