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  • asp.net文件下载

    这个是比较好用的下载文件的代码,可以下载大文件,资源占用小,可以限速,但是如果限速了就容易死机(在线的人多时),取之于网络
    /// <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>

        public  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 = 1024//1K bytes
                    
    //int sleep = 200;   //每秒5次   即5*10K bytes每秒
                    int sleep = (int)Math.Floor((decimal)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=" + System.Web.HttpUtility.UrlEncode(fileName));

                    br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
                    
    int maxCount = (int)Math.Floor((decimal)(fileLength - startBytes) / pack) + 1;

                    
    for (int i = 0; i < maxCount; i++)
                    
    {
                        
    if (Response.IsClientConnected)
                        
    {
                            Response.BinaryWrite(br.ReadBytes(pack));
                            
    //Thread.Sleep(sleep);//有问题,容易导致死机状态,只有设置了这里才可以限速,但在线人多时容易死机
                        }

                        
    else
                        
    {
                            i 
    = maxCount;
                        }

                    }

                }

                
    catch
                
    {
                    
    return false;
                }

                
    finally
                
    {
                    br.Close();
                    myFile.Close();
                }

            }

            
    catch
            
    {
                
    return false;
            }

            
    return true;
        }
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  • 原文地址:https://www.cnblogs.com/ringwang/p/1048007.html
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