.net 附件下载

突然感觉现在爱上了博客园，在这里可以看到许多网友的分享，可以一起平复受伤的心，所以，我也要充分利用博客园，将自已之前零零散散记录在记事本中的总结，记录在这里。与大家一起学习，也方便自己使用。

本节总结，几种下载文件的方法，也是从网上搜到的。

//TransmitFile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.Clear();
    Response.ClearContent();
    Response.ClearHeaders();
    Response.ContentType = "application/octet-stream";
    Response.AddHeader("Content-Disposition", "attachment;filename="+HttpUtility.UrlEncode("中国建设银行Ｅ路护航网银安全组件（大明）.rar",Encoding.UTF8));
    string filename = Server.MapPath("中国建设银行Ｅ路护航网银安全组件（大明）.rar");
    Response.TransmitFile(filename);
}
//流下载
protected void Button2_Click(object sender, EventArgs e)
{
    string fileName = "下载文件.rar";//客户端保存的文件名    
    string filePath = Server.MapPath(fileName);//转化为当前项目下的路径    
    FileInfo fileInfo = new FileInfo(filePath);     
    Response.Clear();   
    Response.ClearContent();    
    Response.ClearHeaders();
    Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileName, Encoding.UTF8));   
    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();
 
}
 /// <summary>
/// 分块下载文件
/// </summary>
/// <param name="strPath">文件的相对路径</param>
/// <param name="fileName">文件名称</param>
protected void fileDown(string strPath, string fileName)
{
    string filePath = Server.MapPath(strPath);//转化为当前项目下的路径     
    System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
    if (fileInfo.Exists == true)
    {  //文件存在
        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, Encoding.UTF8));
        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.Flush();
        Response.End();
        Response.Close();
    }
    else
    {              
        Response.Write("<script>window.opener=null;window.open('','_top');alert('文件不存在！');window.top.close();</script>");
        
    }
}

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.ReadAllBytes(FilePath));

　　WebForm.Response.End();

}