ASP.NET 文件断点续传实现代码

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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 DFile : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void LinBtnDFile_Click(object sender, EventArgs e)
{
// 创建一比特数组
byte[] buffer = new Byte[10240];
// 指定要下载文件的路径.
string filePath = @"D:\爱智旮旯.rar";
// 或取文件名包括扩展名
string fileName = Path.GetFileName(filePath);
Stream fileStream = null;
try
{
// 打开文件
fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
Response.Clear();
// 获取文件的大小
long fileSize = fileStream.Length;
long sum = 0;
if (Request.Headers["Range"] != null)
{
Response.StatusCode = 206; // 表示返回到客户端的 HTTP 输出状态的整数。默认值为 200。
sum = long.Parse(Request.Headers["Range"].Replace("bytes=", "").Replace("-", ""));
}
if (sum != 0)
{
Response.AddHeader("Content-Range", "bytes " + sum.ToString() + "-" + ((long)(fileSize)).ToString() + "/" + fileSize.ToString());
}
// 获取部分http头信息
Response.AddHeader("Content-Length", ((long)(fileSize - sum)).ToString());
Response.ContentType = "application/octet-stream";
//获取文件来源
Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(Request.ContentEncoding.GetBytes(fileName)));
// Response.Flush();
fileStream.Position = sum; //设置当前流位置
fileSize = fileSize - sum;
// 当文件大小大于0是进入循环
while (fileSize > 0)
{
// 判断客户端是否仍连接在服务器
if (Response.IsClientConnected)
{
// 获取缓冲区中的总字节数.
int length = fileStream.Read(buffer, 0, 10240);
// 写入数据
Response.OutputStream.Write(buffer, 0, length);
// 将缓冲区的输出发送到客户端
Response.Flush();
buffer = new Byte[10240];
fileSize = fileSize - length;
}
else
{
//当用户断开后退出循环
fileSize = -1;
}
}
}
catch (Exception ex)
{
Response.Write("Error : " + ex.Message);
}
finally
{
if (fileStream != null)
{
//关闭文件
fileStream.Close();
}
Response.End();
}
}
}