Asp.Net实现文件下载的几种方式

第一种下载方式：

   Label Label5 = GridView1.Rows[e.RowIndex].Cells[0].Controls[0].FindControl("Label5") as Label;
                Response.ContentType = "application/x-zip-compressed";
                Response.AddHeader("Content-Disposition", "attachment;filename=" + Label5.Text.Trim() + "");
                string filename = Server.MapPath("gxxz/upload/" + Label5.Text.Trim());
                Response.TransmitFile(filename);

第二种下载方式：

Label Label5 = GridView1.Rows[e.RowIndex].Cells[0].Controls[0].FindControl("Label5") as Label;
    		string fileName = Label5.Text.Trim();//客户端保存的文件名
    		string filePath = Server.MapPath("gxxz/upload/" + Label5.Text.Trim());//路径
    		FileInfo fileInfo = new FileInfo(filePath);
    		Response.Clear();
    		Response.ClearContent();
    		Response.ClearHeaders();
    		Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
    		Response.AddHeader("Content-Length", fileInfo.Length.ToString());
    		Response.AddHeader("Content-Transfer-Encoding", "binary");
    		Response.ContentType = "application/octet-stream";
    		Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
    		Response.WriteFile(fileInfo.FullName);
    		Response.Flush();
    		Response.End();

第三种下载方式：

	Label Label5 = GridView1.Rows[e.RowIndex].Cells[0].Controls[0].FindControl("Label5") as Label;
            	string fileName = Label5.Text.Trim();//客户端保存的文件名
            	string filePath = Server.MapPath("gxxz/upload/" + Label5.Text.Trim());//路径
            	FileInfo info = new FileInfo(filePath);
            	long fileSize = info.Length;
            	Response.Clear();
            	Response.ContentType = "application/x-zip-compressed";
            	Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
            	//不指明Content-Length用Flush的话不会显示下载进度 
            	Response.AddHeader("Content-Length", fileSize.ToString());
            	Response.TransmitFile(filePath, 0, fileSize);
            	Response.Flush();
            	Response.Close(); 

第四种下载方式：

string fileName = "CodeShark.zip";//客户端保存的文件名
    		string filePath = Server.MapPath("DownLoad/CodeShark.zip");//路径
   		System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
       		 if (fileInfo.Exists == true)
        	{
                   const long ChunkSize = 102400;//100K 每次读取文件，只读取100Ｋ，这样可以缓解服务器的压力
      		   byte[] buffer = new byte[ChunkSize];
           	   Response.Clear();
            	   System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
            	   long dataLengthToRead = iStream.Length;//获取下载的文件总大小
      	           Response.ContentType = "application/octet-stream";
            	   Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
            	     while (dataLengthToRead > 0 && Response.IsClientConnected)
            	    {
                	 int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小
        		 Response.OutputStream.Write(buffer, 0, lengthRead);
               		 Response.Flush();
               		 dataLengthToRead = dataLengthToRead - lengthRead;
            	     }
        	   Response.Close();
        	}