C# · 12月 28, 2021

C#中使用HttpDownLoadHelper下载文件实例

本文实例讲述了C#使用HttpDownLoadHelper下载文件的方法。分享给大家供大家参考。具体实现方法如下:

复制代码 代码如下:using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using System.Threading;

namespace ProjectWenDangManage.Framework
{
/// <summary>
/// HTTP文件下载辅助类
/// </summary>
public class HttpDownLoadHelper
{
/// <summary>
/// 文件下载
/// </summary>
/// <param name=”_Request”></param>
/// <param name=”_Response”></param>
/// <param name=”_fileName”>下载文件时的短文件名称</param>
/// <param name=”_fullPath”>待下载文件的绝对路径</param>
/// <param name=”_speed”>下载速度</param>
/// <returns></returns>
public static bool ResponseFile(HttpRequest _Request,HttpResponse _Response,string _fileName,string _fullPath,long _speed)
{
try
{
FileStream myFile = new FileStream(_fullPath,FileMode.Open,FileAccess.Read,FileShare.ReadWrite);
BinaryReader br = new BinaryReader(myFile);
try
{
_response.addheader(“Accept-Ranges”,”bytes”);
_Response.Buffer = false;
long fileLength = myFile.Length;
long startBytes = 0;

double pack = 10240; //10K bytes
//int sleep = 200; //每秒5次 即5*10K bytes每秒
int sleep = (int)Math.Floor(1000 * pack / _speed) + 1;
if (_Request.Headers[“Range”] != null)
{
_Response.StatusCode = 206;
string[] range = _Request.Headers[“Range”].Split(new char[] { ‘=’,’-‘ });
startBytes = Convert.ToInt64(range[1]);
}
_response.addheader(“Content-Length”,(fileLength – startBytes).ToString());
if (startBytes != 0)
{
//response.addheader(“Content-Range”,string.Format(” bytes {0}-{1}/{2}”,startBytes,fileLength-1,fileLength));
}
_response.addheader(“Connection”,”Keep-Alive”);
_Response.ContentType = “application/octet-stream”;
_response.addheader(“Content-Disposition”,”attachment;filename=” + HttpUtility.UrlEncode(_fileName,System.Text.Encoding.UTF8));

br.BaseStream.Seek(startBytes,SeekOrigin.Begin);
int maxCount = (int)Math.Floor((fileLength – startBytes) / pack) + 1;

for (int i = 0; i < maxCount; i++)
{
if (_Response.IsClientConnected)
{
_Response.BinaryWrite(br.ReadBytes(int.Parse(pack.ToString())));
Thread.Sleep(sleep);
}
else
{
i = maxCount;
}
}
return true;
}
catch
{
return false;
}
finally
{
br.Close();

myFile.Close();
}
}
catch
{
return false;
}
}
}
}

HttpDownLoadHelper

在webfrom中:

复制代码 代码如下:string filePath=Path.Combine(HttpRuntime.AppDomainAppPath,”Files”,”项目管理工具.msi”);
HttpDownLoadHelper.ResponseFile(Request,Response,”下载显示的名称”,filePath,102400);

在mvc中:

复制代码 代码如下:string filePath=Path.Combine(HttpRuntime.AppDomainAppPath,”项目管理工具.msi”);
HttpDownLoadHelper.ResponseFile(HttpContext.ApplicationInstance.Context.Request,HttpContext.ApplicationInstance.Context.Response,102400);

希望本文所述对大家的C#程序设计有所帮助。