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  • [转] ASP.NET下载文件

    Page_Load中添加这样的代码:

    View Code
        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:

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

            return false;
        }
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  • 原文地址:https://www.cnblogs.com/cuishao1985/p/2580648.html
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