多文件上传问题

Question

Try
            'Dim itemi As Int16
            'For itemi = 0 To ddlUploadedImages.Items.Count - 1 '如果此图片已经选择,则退出
            '    If ddlUploadedImages.Items.Item(itemi).Text = File1.PostedFile.FileName Then
            '        txtImageNote.Text = ""
            '        TextBox6.Text = ""
            '        Exit Sub
            '    End If
            'Next
            If File1.PostedFile.FileName <> "" Then '选择一个文件,并且为下面的指定格式,则向ddluploadedimages、dropdownlist2、dropdownlist3添加相应项目
                If Not (File1.PostedFile.FileName.ToString.ToLower.EndsWith(".exe") Or File1.PostedFile.FileName.ToString.ToLower.EndsWith(".dat")) Then                    Dim strBaseLocation As String                    strBaseLocation = Server.MapPath("")                    strBaseLocation = Replace(strBaseLocation, "\", "\\")
                    strBaseLocation = strBaseLocation + "\\images\\"
                    Dim tempFileName, tempFileExtendedName, uploadFileName As String
                    Dim ExtendedIndex As Int16
                    tempFileName = File1.PostedFile.FileName
                    ExtendedIndex = tempFileName.LastIndexOf(".")
                    tempFileExtendedName = Mid(tempFileName, ExtendedIndex + 2)
                    '新生成一时间为标记的文件名
                    uploadFileName = System.DateTime.Now.Year.ToString & System.DateTime.Now.Month.ToString & System.DateTime.Now.Day.ToString & System.DateTime.Now.Hour.ToString & System.DateTime.Now.Minute.ToString & System.DateTime.Now.Second.ToString & "." & tempFileExtendedName
                    File1.PostedFile.SaveAs(strBaseLocation & uploadFileName)
                    ''****
                    messagepublish.MessageId = lblHiddenId.Text.Trim
                    messagepublish.addpicture(txtImageNote.Text.Trim, "images\" & uploadFileName, "") '向qwebt_tpxx中添加一条记录
                    Dim lstItem As ListItem
                    lstItem = New ListItem(uploadFileName, messagepublish.PictureCode)
                    ddlUploadedImages.Items.Add(lstItem)
                    ddlUploadedImages.SelectedIndex = ddlUploadedImages.Items.Count - 1
                    If ddlUploadedImages.Items.Count = 0 Then btnDeleteImage.Visible = True
                    Dim strselectedimageurl As String
                    '获得选择图片在服务器上的路径
                    strselectedimageurl = "Upload\" & ddlUploadedImages.SelectedItem.Text.Trim
                    '显示该图片
                    ' imgview.ImageUrl = Trim(Replace(strselectedimageurl, "\", "/"))                Else
                    Response.Write("<script language=javascript>alert(""上传文件格式不对！"")</script>")
                End If
            End If
            txtImageNote.Text = ""            If ddlUploadedImages.Items.Count > 0 Then
                ddlUploadedImages.Visible = True
                '  imgview.Visible = True
                btnDeleteImage.Visible = True
            End If
            '   Response.Write("<script language='JavaScript'>parent.location.href=""#_1"";</script>")
        Catch enull As NullReferenceException
            Response.Write(enull.Message.ToString)
        End Try