ASP 是一项微软公司的技术，是一种使嵌入网页中的脚本，可由因特网服务器执行的服务器端脚本技术。下面是小编为大家带来了一篇asp.net下载文件的方法，希望对大家有所帮助。

asp.net下载文件的方法(一)

public class FileDown

{

public FileDown()

{ }

/// <summary>

/// 参数为虚拟路径

/// </summary>

public static string FileNameExtension(string FileName)

{

return Path.GetExtension(MapPathFile(FileName));

}

/// <summary>

/// asp.net下载文件的方法：获取物理地址

/// </summary>

public static string MapPathFile(string FileName)

{

return HttpContext.Current.Server.MapPath(FileName);

}

/// <summary>

/// 普通下载

/// </summary>

/// <param name="FileName">文件虚拟路径</param>

public static void DownLoadold(string FileName)

{

string destFileName = MapPathFile(FileName);

if (File.Exists(destFileName))

{

FileInfo fi = new FileInfo(destFileName);

HttpContext.Current.Response.Clear();

HttpContext.Current.Response.ClearHeaders();

HttpContext.Current.Response.Buffer = false;

HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(Path.GetFileName(destFileName), System.Text.Encoding.UTF8));

HttpContext.Current.Response.AppendHeader("Content-Length", fi.Length.ToString());

HttpContext.Current.Response.ContentType = "application/octet-stream";

HttpContext.Current.Response.WriteFile(destFileName);

HttpContext.Current.Response.Flush();

HttpContext.Current.Response.End();

}

}

/// <summary>

/// asp.net分块下载

/// </summary>

/// <param name="FileName">文件虚拟路径</param>

public static void DownLoad(string FileName)

{

string filePath = MapPathFile(FileName);

long chunkSize = 204800; //指定块大小

byte[] buffer = new byte[chunkSize]; //建立一个200K的缓冲区

long dataToRead = 0; //已读的字节数

FileStream stream = null;

try

{

//打开文件

stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);

dataToRead = stream.Length;

//添加Http头

HttpContext.Current.Response.ContentType = "application/octet-stream";

HttpContext.Current.Response.AddHeader("Content-Disposition", "attachement;filename=" + HttpUtility.UrlEncode(Path.GetFileName(filePath)));

HttpContext.Current.Response.AddHeader("Content-Length", dataToRead.ToString());

while (dataToRead > 0)

{

if (HttpContext.Current.Response.IsClientConnected)

{

int length = stream.Read(buffer, 0, Convert.ToInt32(chunkSize));

HttpContext.Current.Response.OutputStream.Write(buffer, 0, length);

HttpContext.Current.Response.Flush();

HttpContext.Current.Response.Clear();

dataToRead -= length;

}

else

{

dataToRead = -1; //防止client失去连接

}

}

}

catch (Exception ex)

{

HttpContext.Current.Response.Write("Error:" + ex.Message);

}

finally

{

if (stream != null) stream.Close();

HttpContext.Current.Response.Close();

}

}

/// <summary>

/// 输出硬盘文件，提供下载 支持大文件、续传、速度限制、资源占用小

/// </summary>

/// <param name="_Request">Page.Request对象</param>

/// <param name="_Response">Page.Response对象</param>

/// <param name="_fileName">下载文件名</param>

/// <param name="_fullPath">带文件名下载路径</param>

/// <param name="_speed">每秒允许下载的字节数</param>

/// <returns>返回是否成功</returns>

//---------------------------------------------------------------------

//调用：

// string FullPath=Server.MapPath("count.txt");

// ResponseFile(this.Request,this.Response,"count.txt",FullPath,100);

//---------------------------------------------------------------------

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;

int pack = 10240; //10K bytes

int sleep = (int)Math.Floor((double)(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((double)((fileLength - startBytes) / pack)) + 1;

for (int i = 0; i < maxCount; i++)

{

if (_Response.IsClientConnected)

{

_Response.BinaryWrite(br.ReadBytes(pack));

Thread.Sleep(sleep);

}

else

{

i = maxCount;

}

}

}

catch

{

return false;

}

finally

{

br.Close();

myFile.Close();

}

}

catch

{

return false;

}

return true;

}

}

asp.net下载文件的方法(二)

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

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

3

4 System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);

5

6 if (fileInfo.Exists == true)

7 {

8 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

9 byte[] buffer = new byte[ChunkSize];

10

11 Response.Clear();

12 System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);

13 long dataLengthToRead = iStream.Length;//获取下载的文件总大小

14 Response.ContentType = "application/octet-stream";

15 Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));

16 while (dataLengthToRead > 0 && Response.IsClientConnected)

17 {

18 int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小

19 Response.OutputStream.Write(buffer, 0, lengthRead);

20 Response.Flush();

21 dataLengthToRead = dataLengthToRead - lengthRead;

22 }

23 Response.Close();

24 }