C#怎么实现文件下载功能的四种方法

来源：互联网发布：淘宝csv数据包裂变编辑：程序博客网时间：2024/04/29 16:54
using System;using System.Data;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.IO;public partial class _Default : System.Web.UI.Page {    protected void Page_Load(object sender, EventArgs e)    {    }    //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";        string FileName = "test.doc";        //使用UTF-8对文件名进行编码        Response.AppendHeader("Content-Disposition", "attachment;filename=\"" + HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8) + "\"");        Response.ContentType = "application/octet-stream";        Response.AddHeader("Content-Disposition", "attachment;filename=" + FileName);        string filename = Server.MapPath("../ReportTemplate/test.doc");        Response.TransmitFile(filename);    }    //WriteFile实现下载    protected void Button2_Click(object sender, EventArgs e)    {         /*         using System.IO;                  */        string fileName = "test.doc";//客户端保存的文件名        string filePath = Server.MapPath("../ReportTemplate/test.doc");//路径        FileInfo fileInfo = new FileInfo(filePath);        Response.Clear();        Response.ClearContent();        Response.ClearHeaders();        Response.AddHeader("Content-Disposition", "attachment;filename=\"" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8) + "\"");        Response.AddHeader("Content-Length", fileInfo.Length.ToString());        Response.AddHeader("Content-Transfer-Encoding", "binary");        Response.ContentType = "application/octet-stream";        Response.WriteFile(fileInfo.FullName);        Response.Flush();        Response.End();    }    //WriteFile分块下载    protected void Button3_Click(object sender, EventArgs e)    {        string fileName = "test.doc";//客户端保存的文件名        string filePath = Server.MapPath("../ReportTemplate/test.doc");//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, System.Text.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.Close();        }    }    //流方式下载    protected void Button4_Click(object sender, EventArgs e)    {        string fileName = "test.doc";//客户端保存的文件名        string filePath = Server.MapPath("../ReportTemplate/test.doc");//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();    }}
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