System.ObjectDisposedException: Cannot access a closed file

Question

本人想批量上传照片，在local的时候，一切功能都正常，上传文件存数据库以及存相片文件夹都正常。
可是当把程序放到server上，上传一张照片就会报错，当上传四张以上，第一张正常，第二张以后就抱错，抱错的代码为：file.SaveAs(Server.MapPath(relativepath));察看log里面的纪录说是：System.ObjectDisposedException: Cannot access a closed file.
不知道为什么了，恳请大家帮忙！谢谢！

Answer 1

    protected void btnSave_Click(object sender, EventArgs e)
    {
        if (Session["HttpPostedFileSession"] != null)
        {
            List<HttpPostedFile> postedFileList = (List<HttpPostedFile>)Session["HttpPostedFileSession"];            foreach (HttpPostedFile f in postedFileList)
            {
                //f.SaveAs(HttpContext.Current.Request.PhysicalApplicationPath + "FileModule/MultiUploader/upload/" + f.FileName);                HttpFileCollection uploadFile = Request.Files;
                string fileFormat, fileName, GUIDName, GUIDFileName;
                int fileTypeID = int.Parse(ddlFileTypeDropDown.selectedValue);
                string extensionType = FileModule.FileTypeTable.getExtensionByFileTypeID(fileTypeID);            if (!string.IsNullOrEmpty(f.FileName))
            {
                string[] file = f.FileName.Split('.');
                fileFormat = file[1];
                fileName = file[0];                GUIDFileName = System.Guid.NewGuid().ToString();
                GUIDName = GUIDFileName + "." + fileFormat;
if (extensionType.Contains(fileFormat))
                    {
                        try
                        {
                            string memberZone = FileModule.FileModuleType.getModulePath(moduleType) + moduleID + Path.AltDirectorySeparatorChar + FileModule.FileTypeTable.getTypeName(ddlFileTypeDropDown.selectedValue) + Path.AltDirectorySeparatorChar;
                            string relativepath = memberZone + GUIDName;
                            f.SaveAs(Server.MapPath(relativepath));                            if (File.Exists(Server.MapPath(relativepath)))
                            {                                if (saveToDB(f.FileName, relativepath))
                                {
                                    lblmsg.Text ="Upload Successfully @" + DateTime.Now;
                                    if (this.UpdateResultEvent != null)
                                    {
                                        this.UpdateResultEvent(true);
                                    }                                }
                                else
                                {
                                    File.Delete(Server.MapPath(relativepath));
                                    lblmsg.Text = "Insert Fail";
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            Common.writelog(ex.ToString());
                            lblmsg.Text = "Fail Upload";
                        }
                    }
                    else
                    {
                        lblmsg.Text = "Incorrect File Type!";
                    }
                }                else
                {
                    lblmsg.Text = "Please Upload a File";
                }            }
        
        Session.Clear();
        }
    }

Answer 2

是不是文件超过限制呢！看看webconfig 的httpRuntime节