ASP .net 实现文件上传 下载功能

ASP .net 实现文件上传 下载功能

一、文件上传

1、单文件上传

利用FileUpload控件完成上传功能

代码：

string filepath = FileUpload1.PostedFile.FileName;

string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);

string serverpath = Server.MapPath("File/") + filename;

FileUpload1.PostedFile.SaveAs(serverpath);

2、多文件上传

代码：

string FilePath = Server.MapPath("./") + "File";

HttpFileCollection HFC = Request.Files;

for (int i = 0; i < HFC.Count; i++)

{

HttpPostedFile UserHPF = HFC[i];

try

{

if (UserHPF.ContentLength > 0)

{

UserHPF.SaveAs(FilePath + "\\" + System.IO.Path.GetFileName(UserHPF.FileName));

}

}

catch

{

Label1.Text = "处理出错！";

}
}

3、传送大文件

修改web.config

<httpRuntime maxRequestLength="40960" executionTimeout="6000"/>

maxRequestLength:最大上传容量

executionTimeout：响应的时间

二、文件下载

代码：

//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.Clear(); //解决txt中出现乱码

Response.ContentType = "application/x-zip-compressed";

Response.AddHeader("Content-Disposition", "attachment;filename="+Server.UrlEncode("辛苦.zip"));//解决文件名中文乱码

string filename = Server.MapPath("DownLoad/aaa.zip");

Response.TransmitFile(filename);

Response.End(); //解决txt中出现乱码

}

//WriteFile实现下载

protected void Button2_Click(object sender, EventArgs e)

{

/*

using System.IO;

*/
string fileName ="aaa.zip";//客户端保存的文件名

string filePath=Server.MapPath("DownLoad/aaa.zip");//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();

}

//WriteFile分块下载

protected void Button3_Click(object sender, EventArgs e)

{
string fileName = "aaa.zip";//客户端保存的文件名

string filePath = Server.MapPath("DownLoad/aaa.zip");//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();

}

}

//流方式下载

protected void Button4_Click(object sender, EventArgs e)

{

string fileName = "aaa.zip";//客户端保存的文件名

string filePath = Server.MapPath("DownLoad/aaa.zip");//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();
}