C# 实现动态输出下载文件内容实现隐藏真实路径的功能

一、//TransmitFile实现下载
    protected void Button1_Click(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:
       
*/
        Response.ContentType
= "application/x-zip-compressed";
        Response.AddHeader(
"Content-Disposition", "attachment;filename=z.zip");
       
string filename = Server.MapPath("DownLoad/z.zip");
        Response.TransmitFile(filename);
    }

二、//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();
    }

三、   //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();
        }
    }

四、//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();
    }

//———————————————————-

public void DownloadFile( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FileBody )
{

  WebForm.Response.ClearHeaders();
  WebForm.Response.Clear();
  WebForm.Response.Expires = 0;
  WebForm.Response.Buffer
= true;
  WebForm.Response.AddHeader(
"Accept-Language", "zh-tw");
  
//‘文件名称
  WebForm.Response.AddHeader("content-disposition", "attachment; filename=’"+System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8)+"");
  WebForm.Response.ContentType
= "Application/octet-stream";
  
//‘文件内容
  WebForm.Response.Write(FileBody);//———–
    WebForm.Response.End();
}

//上面这段代码是下载一个动态产生的文本文件,若这个文件已经存在于服务器端的实体路径,则可以通过下面的函数:

public void DownloadFileByFilePath( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FilePath )
{
  WebForm.Response.ClearHeaders();
  WebForm.Response.Clear();
  WebForm.Response.Expires
= 0;
    WebForm.Response.Buffer
= true;
  WebForm.Response.AddHeader(
"Accept-Language", "zh-tw");
  
//文件名称
  WebForm.Response.AddHeader("content-disposition", "attachment; filename=’" + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) +"" );
  WebForm.Response.ContentType
= "Application/octet-stream";
  
//文件内容
  WebForm.Response.Write(System.IO.File.Rea}dAllBytes(FilePath));//———
  WebForm.Response.End();

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