[转] ASP.NET下载文件

Page_Load中添加这样的代码:

 

    protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
    {
        Page.Response.Clear();
        if (!isFile(this.TreeView1.SelectedValue)) return;
        bool success = ResponseFile(Page.Request, Page.Response, new FileInfo(this.TreeView1.SelectedValue).Name, this.TreeView1.SelectedValue, 1024000);
        if (!success)
            Response.Write("下载文件出错！");
        Page.Response.End();
    }

 

文件下载函数代码为:

 

 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;
                    }
                }
            }
            catch
            {
                return false;
            }
            finally
            {
                br.Close();

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

 

private bool isFile(string path)
    {
        if (Directory.Exists(path))
            return false;
        else if (File.Exists(path))
            return true;

        return false;
    }