用Response.OutputStream.Write点【取消】按钮导致IIS崩溃，重金悬赏解决方案

[wdf618]

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string baseFolder = System.Web.HttpContext.Current.Server.MapPath(".");
        baseFolder += "\\wdt_m21\\Files_in\\lhpy\\";
        string fn = "LHPY_0659H4FCRW2011_05_06_19_26_589UCIV040C5_271719373042.pdf";
        FileDownload(baseFolder, fn, "", "");
    }

    public static void FileDownload(string FilePath, string FileName, string FileType, string FileTitle)
    {
        string strFullFileName = FilePath + FileName;

        long chunkSize = 102400;  //建立一个100K的缓冲区    
        byte[] buffer = new byte[chunkSize];
        long dataToRead = 0;//已读的字节数 
        FileStream stream = null;

       
            stream = new FileStream(strFullFileName, FileMode.Open, FileAccess.Read, FileShare.Read);
            dataToRead = stream.Length;

            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ClearHeaders();
            HttpContext.Current.Response.Buffer = false;

            if (FileType == "")
            {
                FileType = FileName.Substring(FileName.LastIndexOf(".") + 1);
            }
            switch (FileType.ToString().ToUpper())
            {
                case "XLS":
                    HttpContext.Current.Response.ContentType = "application/ms-excel";
                    break;
                case "DOC":
                    HttpContext.Current.Response.ContentType = "application/ms-word";
                    break;
                case "TXT":
                    HttpContext.Current.Response.ContentType = "application/text";
                    break;
                case "PDF":
                    HttpContext.Current.Response.ContentType = "application/pdf";
                    break;
                case "GIF":
                    HttpContext.Current.Response.ContentType = "images/gif";
                    break;
                case "JPG":
                    HttpContext.Current.Response.ContentType = "images/jpg";
                    break;
            }
            HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8));
            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.End();
                    HttpContext.Current.Response.Flush();
                    HttpContext.Current.Response.Clear();
                    dataToRead -= length;
                }
                else
                {
                    dataToRead = -1; //防止client失去连接 
                }
            }

            //HttpContext.Current.Response.End();

        
          
        
    }
}

以上代码为利用缓冲区提供文件下载的代码，运行Button1_Click后会蹦出文件下载对话框，如果点【打开】或者【保存】都没问题，文件可以高效的下载完成，但是如果点【取消】，IIS就会崩溃。有时候点取消后需要等几秒钟，这几秒钟内网站还可以有响应，但是随即就崩溃了。

请各位修改上述代码以解决该问题

[luofeng0710]

把代码try一下，在finally里面释放资源。

[wdf618]

[Quote=引用 23 楼 luofeng0710 的回复:]
把代码try一下，在finally里面释放资源。
[/Quote]

这样写了问题依旧存在：

       public static void FileDownload(string FilePath,string FileName,string FileType, string FileTitle)
        {
            string strFullFileName = FilePath + FileName ;

            long chunkSize = 102400;  //建立一个100K的缓冲区    
            byte[] buffer = new byte[chunkSize];
            long dataToRead = 0;//已读的字节数 
            FileStream stream = null;    

            try
            {
                using (stream = new FileStream(strFullFileName, FileMode.Open, FileAccess.Read, FileShare.Read))
                {
                    dataToRead = stream.Length;

                    HttpContext.Current.Response.Clear();
                    HttpContext.Current.Response.ClearHeaders();
                    HttpContext.Current.Response.Buffer = true;

                    if (FileType == "")
                    {
                        FileType = FileName.Substring(FileName.LastIndexOf(".") + 1);
                    }
                    switch (FileType.ToString().ToUpper())
                    {
                        case "XLS":
                            HttpContext.Current.Response.ContentType = "application/ms-excel";
                            break;
                        case "DOC":
                            HttpContext.Current.Response.ContentType = "application/ms-word";
                            break;
                        case "TXT":
                            HttpContext.Current.Response.ContentType = "application/text";
                            break;
                        case "PDF":
                            HttpContext.Current.Response.ContentType = "application/pdf";
                            break;
                        case "GIF":
                            HttpContext.Current.Response.ContentType = "images/gif";
                            break;
                        case "JPG":
                            HttpContext.Current.Response.ContentType = "images/jpg";
                            break;
                    }
                    HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8));
                    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)
            {
                SysOverlook mylog = new SysOverlook();
                mylog.RecordSysError("FileDownload", ex.Message);

                HttpContext.Current.Response.Clear();
                HttpContext.Current.Response.ClearHeaders();
                HttpContext.Current.Response.Buffer = false;
                HttpContext.Current.Response.ContentType = "application/octet-stream";
                HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=Error.txt");
                HttpContext.Current.Response.Write("下载失败！");
                HttpContext.Current.Response.Flush();
                HttpContext.Current.Response.End();
            }
            finally
            {
                if (stream != null)
                {
                    stream.Close();
                }
                HttpContext.Current.Response.Close();
                
            }   
        }

[xuexiaodong2009]

等牛人解决吧

[wdf618]

最新的代码写成了这样：

  public static void FileDownload(string FilePath, string FileName, string FileType, string FileTitle)
    {


        try
        {
            string strFullFileName = FilePath + FileName;

            long chunkSize = 102400;  //建立一个100K的缓冲区    
            byte[] buffer = new byte[chunkSize];
            long dataToRead = 0;//已读的字节数               

            using (FileStream stream = new FileStream(strFullFileName, FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                dataToRead = stream.Length;

                HttpContext.Current.Response.Clear();
                HttpContext.Current.Response.ClearHeaders();
                HttpContext.Current.Response.Buffer = false;

                if (FileType == "")
                {
                    FileType = FileName.Substring(FileName.LastIndexOf(".") + 1);
                }
                switch (FileType.ToString().ToUpper())
                {
                    case "XLS":
                        HttpContext.Current.Response.ContentType = "application/ms-excel";
                        break;
                    case "DOC":
                        HttpContext.Current.Response.ContentType = "application/ms-word";
                        break;
                    case "TXT":
                        HttpContext.Current.Response.ContentType = "application/text";
                        break;
                    case "PDF":
                        HttpContext.Current.Response.ContentType = "application/pdf";
                        break;
                    case "GIF":
                        HttpContext.Current.Response.ContentType = "images/gif";
                        break;
                    case "JPG":
                        HttpContext.Current.Response.ContentType = "images/jpg";
                        break;
                }
                HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8));
                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.Clear();
            HttpContext.Current.Response.ClearHeaders();
            HttpContext.Current.Response.Buffer = false;
            HttpContext.Current.Response.ContentType = "application/octet-stream";
            HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=Error.txt");
            HttpContext.Current.Response.Write("下载失败！");
            HttpContext.Current.Response.Flush();
            HttpContext.Current.Response.End();
        }
        finally
        {

            HttpContext.Current.Response.Close();

        }
    }

问题依旧存在！！！

补充一个发现：在vs2010的调试状态下，该问题不存在，但在iis上运行时该问题很突出

[子夜__]

Response.Clear();
Response.End();

[wdf618]

[Quote=引用 27 楼 wxr0323 的回复:]
Response.Clear();
Response.End();
[/Quote]

   finally
        {

            //HttpContext.Current.Response.Close();
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.End();
        }

这么写了，无效~~~~问题依旧~

[IE11下面经常卡到爆]

[Quote=引用 3 楼 wdf618 的回复:]
引用 2 楼 xuexiaodong2009 的回复:
取消是不是也进FileDownload(string FilePath, string FileName, string FileType, string FileTitle)里边了？

是啊，不进去怎么能弹出下载框呢？
[/Quote]

逻辑问题，点取消为什么还要进去那个方法？点取消就是客户端关闭下载对话框（结束下载Request会话）
while (dataToRead > 0)
{
if (HttpContext.Current.Response.IsClientConnected)
客户端发起的http讲求之间是相互对立的，点取消后当前请求已经断开（虽然用户还在看其他的页面，但那与当前请求无关，服务端处理一个请求的超时时间不过90秒而已
程序进入了死循环。。 {
int length = stream.Read(buffer, 0, Convert.ToInt32(chunkSize));
HttpContext.Current.Response.OutputStream.Write(buffer, 0, length);
//HttpContext.Current.Response.End();
HttpContext.Current.Response.Flush();
HttpContext.Current.Response.Clear();
dataToRead -= length;
}
else
{
dataToRead = -1; //防止client失去连接
}
}

[IE11下面经常卡到爆]

要知道你在看某个网页的时候，但你的那个请求早都已经和服务器断开了（这里不说长连接）就算你断网了它也还在那儿，直到你刷新，你才知道断网了不是吗？

弹提示框那里改一下，自己在网页上做一个吧，JQuery的也很多，直到用户确认下载了，服务端才应该开始去读数据并Response，否则，你都不应该告诉服务器客户端有人取消了某个下载（它会忙死的）

[wdf618]

[Quote=引用 38 楼 xuexiaodong2009 的回复:]
解决不了，还不向上放映？出了事，还不成替罪羊了？
[/Quote]
已经反映了

[wdf618]

[Quote=引用 31 楼 dongxinxi 的回复:]
如果要下载的文件比较大，客户点了下载之后，马上把下载的对话框关掉，你那个程序也会进入
while (dataToRead > 0){.. dataToRead = -1;}中导致IIS工作进程崩溃
改一下吧


C# code


//这里，唯一让服务器持续输出数据的理由只有两个：当前下载请求仍然没有中断，且数据没有输出完毕
while (HttpContext.Current.……
[/Quote]

这样改了问题依旧存在，并未改善。
实际上点了取消之后while循环即终止，不会死循环，因为else中把dataToRead设为了-1，因此循环终止了

[IE11下面经常卡到爆]

你不说点取消后也依然会进入FileDownload方法吗？关键在这里，你的取消事件代码？

[wdf618]

[Quote=引用 33 楼 dongxinxi 的回复:]
你不说点取消后也依然会进入FileDownload方法吗？关键在这里，你的取消事件代码？
[/Quote]
怎么能取消呢？

[xuexiaodong2009]

还是别用while循环下载文件了，能快多少啊？
那个保存取消是浏览器弹出的框，能处理吗？

我一直有的这种方式没有出过错
Response.ClearContent();
Response.ContentType = "image/jpeg";
Response.BinaryWrite(GeneralMethods.FileToByteArray(Server.MapPath(Utilities.DefaultLogoPath)));
Response.End();

[wdf618]

[Quote=引用 35 楼 xuexiaodong2009 的回复:]
还是别用while循环下载文件了，能快多少啊？
那个保存取消是浏览器弹出的框，能处理吗？

我一直有的这种方式没有出过错
Response.ClearContent();
Response.ContentType = "image/jpeg";
Response.BinaryWrite(GeneralMethods.FileToByteArray(Server.MapPath(……
[/Quote]

用这方法不是我决定的，我也是干事的人....按我的想法，小文件直接给个链接大文件FTP就行了

[xuexiaodong2009]

[Quote=引用 36 楼 wdf618 的回复:]

引用 35 楼 xuexiaodong2009 的回复:
还是别用while循环下载文件了，能快多少啊？
那个保存取消是浏览器弹出的框，能处理吗？

我一直有的这种方式没有出过错
Response.ClearContent();
Response.ContentType = "image/jpeg";
Response.BinaryWrite(GeneralMethods.File……
[/Quote]那就把问题告诉他，看他怎么解决IIS死的问题

[xuexiaodong2009]

解决不了，还不向上放映？出了事，还不成替罪羊了？

[IE11下面经常卡到爆]

如果要下载的文件比较大，客户点了下载之后，马上把下载的对话框关掉，你那个程序也会进入
while (dataToRead > 0){.. dataToRead = -1;}中导致IIS工作进程崩溃
改一下吧

//这里，唯一让服务器持续输出数据的理由只有两个：当前下载请求仍然没有中断，且数据没有输出完毕
while (HttpContext.Current.Response.IsClientConnected && dataToRead > 0)
            {
                    int length = stream.Read(buffer, 0, Convert.ToInt32(chunkSize));
                    HttpContext.Current.Response.OutputStream.Write(buffer, 0, length);
                    //HttpContext.Current.Response.End();
                    HttpContext.Current.Response.Flush();
                    HttpContext.Current.Response.Clear();
                    dataToRead -= length;
            }
}

实际上只要HttpContext.Current.Response.IsClientConnected=false了，就应该马上Response.End

[zrdzxh]

同样的问题，折腾了两天；用这个没问题：

                        Response.Clear();
                        Response.ClearContent();
                        Response.ClearHeaders();
                        Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(newFileName));
                        Response.AddHeader("Content-Length", downFile.Length.ToString());
                        Response.AddHeader("Content-Transfer-Encoding", "binary");
                        Response.ContentType = "application/octet-stream";
                        Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
                        Response.WriteFile(downFile.FullName);
                        Response.Flush();
                        Response.End();

[zrdzxh]

丢了两句：

                    string newFileName = 新文件名;
                    string downUrl = Server.MapPath(虚拟路径);

                    FileInfo downFile = new FileInfo(downUrl);

[heriver]

[Quote=引用 41 楼 的回复:]

同样的问题，折腾了两天；用这个没问题：
C# code
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Respo……
[/Quote]

膜拜