下载

我的一个下载程序的代码， 仅供参考：

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.IO;

namespace DDMS
{
 /// <summary>
 /// docDownload 的摘要说明。
 /// </summary>
 public class docDownload : PageBase
 {
  private void Page_Load(object sender, System.EventArgs e)
  {  
   string attachId = Request.QueryString["id"];
   DataRow dr = SqlScope.ExecuteDataRow(@"
select
 contentType,
 fileName,
 fileSize,
 fileExt,
 saveFileName
from
 Attach
where
 id = @p0
",
    attachId);

   if (dr == null)
   {
    return;
   }

   string filePath = Config.UploadPath + dr["saveFileName"].ToString();
   
   // 文件不存在
   if (File.Exists(filePath) == false)
   {
    Response.Write("找不到文件.");
    return;
   }

   string contentType;

   switch (dr["fileExt"].ToString().ToLower())
   {
    case ".asf":
     contentType = "video/x-ms-asf";
     break;
    case ".avi":
     contentType = "video/avi";
     break;
    case ".doc":
     contentType = "application/msword";
     break;
    case ".zip":
     contentType = "application/zip";
     break;
    case ".xls":
     contentType = "application/vnd.ms-excel";
     break;
    case ".gif":
     contentType = "image/gif";
     break;
    case ".jpg":
     contentType = "image/jpeg";
     break;
    case ".jpeg":
     contentType = "image/jpeg";
     break;
    case ".wav":
     contentType = "audio/wav";
     break;
    case ".mp3":
     contentType = "audio/mpeg3";
     break;
    case ".mpg":
     contentType = "video/mpeg";
     break;
    case ".mpeg":
     contentType = "video/mpeg";
     break;
    case ".rtf":
     contentType = "application/rtf";
     break;
    case ".txt":
     contentType = "text/html";
     break;
    default:
     contentType = "application/octet-stream";
     break;
   }

   FileStream fs = File.OpenRead(filePath);
   byte[] content = new byte[fs.Length];
   fs.Read(content, 0, (int) fs.Length);

   Response.Clear();
   Response.AddHeader("Content-Type", contentType);
   Response.Charset = "GB2312";
   if (contentType == "application/octet-stream")
   {
    Response.AddHeader("Content-Disposition", "attachment;filename=" + dr["fileName"].ToString());
    Response.AddHeader("Content-Length", fs.Length.ToString());
   }
   Response.BinaryWrite(content); 
  }
  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }
  
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {   
   this.Load += new System.EventHandler(this.Page_Load);

  }
  #endregion
 }
}