［转］asp.net中实现下载 -优快云博客

/// <param name="_Request">页面的Request对象</param>
    /// <param name="_Response">页面的Response对象</param>
    /// <param name="_fullPath">带文件名的下载路径</param>
    /// <param name="_speed">每秒允许下载的字节数</param>
    /// <returns>返回一个Bool值，true表示下载成功，False表示下载失败</returns>

    public bool ResponseFile(HttpRequest _Request, HttpResponse _Response, 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   =   200;   //每秒5次   即5*10K   bytes每秒
                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(myFile.Name, 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;
    }

// .aspx.cs
void Page_Init(...
{
      Response.Clear();
      bool success = ResponseFile(Request, Response, 文件物理路径, 1024*1024);
      if(success) {
            Response.End();
            // ...
      } else {
            // ...
      }
}

后续：

下载

//方法一
/// <summary>
/// 文件下载
/// </summary>
/// <param name="FullFileName"></param>
private void FileDownload(string FullFileName)
{
FileInfo DownloadFile = new FileInfo(FullFileName);
Response.Clear();
Response.ClearHeaders();
Response.Buffer=false;
Response.ContentType="application/octet-stream";
Response.AppendHeader("Content-Disposition","attachment;filename=" +HttpUtility.UrlEncode(DownloadFile.FullName,System.Text.Encoding.UTF8));
Response.AppendHeader("Content-Length",DownloadFile.Length.ToString());
Response.WriteFile(DownloadFile.FullName);
Response.Flush();
Response.End();
}

//方法二
FileStream fileStream = new FileStream(Server.MapPath(dataUrl),FileMode.Open);
long fileSize = fileStream.Length;
Context.Response.ContentType="application/octet-stream";
Context.Response.AddHeader("Content-Disposition","attachment; filename=/"" + HttpUtility.UrlEncode(fileNameSystem.Text.Encoding.UTF8) + "/"");
Context.Response.AddHeader("Content-Length",fileSize.ToString());
byte[] fileBuffer=new byte[fileSize];
fileStream.Read(fileBuffer, 0, (int)fileSize);
fileStream.Close();
Context.Response.BinaryWrite(fileBuffer);
Context.Response.End();

//方法三
// 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
// 输入参数 _Request: Page.Request对象，  _Response: Page.Response对象， _fileName: 下载文件名， _fullPath: 带文件名下载路径， _speed 每秒允许下载的字节数
// 返回是否成功
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 = 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(pack));
Thread.Sleep(sleep);
}
else
{
i=maxCount;
}
}
}
catch
{
return false;
}
finally
{
br.Close();
myFile.Close();
}
}
catch
{
return false;
}
return true;
}