.net下载文件的常用方法汇总

//TransmitFile实现下载  
         protected void Button1_Click1(object sender, EventArgs e)  
        {  
            /*  
             微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite  
             下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。  
             代码如下：  
             */  
            string strFileName = "三部闲置设备管理系统操作手册IEMS.ppt";  
            Response.ContentType = "application/x-zip-compressed";  
            //Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");  
            string filename = BLL.Config.PART_EM_UPLOAD_DOC + strFileName;   
            //BLL.Config.PART_EM_UPLOAD_DOC 为路径   ("D:/EMUploadDoc/")  
            Response.AddHeader("Content-Disposition", "attachment;filename=" +Server.UrlPathEncode(strFileName));  
           //Server.UrlPathEncode()解决文件名的乱码问题.  
              
            Response.TransmitFile(filename);  
        }    //WriteFile实现下载  
    protected void Button2_Click(object sender, EventArgs e)  
    {  
        /*  
         using System.IO;  
           
         */  
        string fileName = "asd.txt";//客户端保存的文件名  
        string filePath = Server.MapPath("DownLoad/aaa.txt");//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();  
    }  
    //WriteFile分块下载  
    protected void Button3_Click(object sender, EventArgs e)  
    {  
        string fileName = "aaa.txt";//客户端保存的文件名  
        string filePath = Server.MapPath("DownLoad/aaa.txt");//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();  
        }  
    }  
    //流方式下载  
    protected void Button4_Click(object sender, EventArgs e)  
    {  
        string fileName = "aaa.txt";//客户端保存的文件名  
        string filePath = Server.MapPath("DownLoad/aaa.txt");//路径  
        //以字符流的形式下载文件  
        FileStream fs = new FileStream(filePath, FileMode.Open);  
        byte[] bytes = new byte[(int)fs.Length];  
        fs.Read(bytes, 0, bytes.Length);  
        fs.Close();  
        Response.ContentType = "application/octet-stream";  
        //通知浏览器下载文件而不是打开  
        Response.AddHeader("Content-Disposition", "attachment;  filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));  
        Response.BinaryWrite(bytes);  
        Response.Flush();  
        Response.End();  
    }  

 

C#:

/// <summary> /// 文件下载 /// </summary> /// 
 private void FileDownload(string FullFileName) 
{ FileInfo DownloadFile = new FileInfo(FullFileName);
 Response.Clear();
 Response.ClearHeaders();
 Response.Buffer=false; 
Response.ContentType= "application/octet-stream ";
 Response.AppendHeader( "Content-Disposition ", "attachment;filename= " +HttpUtility.UrlEncode(DownloadFile.FullName,System.Text.Encoding.UTF8)); 
Response.AppendHeader( "Content-Length ",DownloadFile.Length.ToString());
 Response.WriteFile(DownloadFile.FullName);
 Response.Flush(); 
Response.End();
 }