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asp.net文件下载的方法

时间:2013-12-25类别:编程学习

asp.net文件下载的方法

asp.net文件下载的方法

ASP.NET文件下载的封装类

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  • C# 代码   复制
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    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>
            /// 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>
            /// 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)
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