Question

在加载页面之前，我使用子例程将DropDownList控件链接在一起：

Private Sub CreateCascadingDropDown(ByVal category As String, ByRef parentDDL As DropDownList, ByRef targetDDL As DropDownList)
            Dim CDDL As New CascadingDropDown
            With CDDL
                .Category = category
                If Not parentDDL Is Nothing Then
                    parentDDL.Items.Clear()
                    .ParentControlID = parentDDL.ID
                End If
                targetDDL.Items.Clear()
                .TargetControlID = targetDDL.ID
                .PromptText = SharedWeb.GC_SELECTONE
                .PromptValue = "-1"
                .LoadingText = "Please wait..."
                .ServicePath = "/ajax/InvestmentProcess.asmx"
                .ServiceMethod = "GetTaxo"
            End With
            'Page.ClientScript.RegisterForEventValidation(CDDL.UniqueID)
            targetDDL.Parent.Controls.Add(CDDL)
        End Sub

调用Web服务方法时，它会执行以下代码。根据类别，它从适配器获取适当的数据。

<WebMethod()> _
    Public Function GetTaxo(ByVal knownCategoryValues As String, ByVal category As String) As CascadingDropDownNameValue()
        Dim log As ILog = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType)
        log.Debug("GetSegmentTaxonomy(" + category + ") -> {" + knownCategoryValues + "}")
        Dim kv As StringDictionary = CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues)
        Dim adapter As New SegmentTaxonomyTableAdapters.SEGMENT_ARCHITECTURE_TableAdapter
        Dim rows As DataRowCollection

        Select Case category
            Case InvestmentEdit.ST_SEG_ARCH
                rows = New SegmentTaxonomyTableAdapters.SEGMENT_ARCHITECTURE_TableAdapter().GetData().Rows
            Case InvestmentEdit.ST_LOB
                If kv.ContainsKey(InvestmentEdit.ST_SEG_ARCH) Then
                    log.Debug("found seg architecture - > " + kv(InvestmentEdit.ST_SEG_ARCH))
                    rows = New SegmentTaxonomyTableAdapters.LINE_OF_BUSINESSTableAdapter().GetData(kv(InvestmentEdit.ST_SEG_ARCH)).Rows
                End If
        End Select

        If Not rows Is Nothing Then
            Dim results As New List(Of CascadingDropDownNameValue)
            For Each row As DataRow In rows
                log.Debug("ROW >>>> " + row("lov_label").ToString() + " : " + row("lov_cd").ToString())
                results.Add(New CascadingDropDownNameValue(row("lov_label"), row("lov_cd")))
            Next
            Return results.ToArray
        End If
        Return Nothing
    End Function

我需要将大约5个下拉链接在一起。顶级下拉控件（myDDL）加载正常，如果它是唯一链接如下：

CreateCascadingDropDown("MyCat",Nothing,myDDL)

但是当我链接第二个下拉控件时，Internet Explorer会给脚本超时。如果我继续允许脚本运行，它只是不断给我提示。如果选择停止运行脚本，我会得到方法错误12031或错误500（是的，我在我的Web服务文件中有ScriptService（）声明）。关于导致这种情况的任何想法？

Answer 1

事实证明我只需要从Ajax Control Toolkit中添加以下控件：

<ajax:ToolkitScriptManager ID="tsm" runat="server" />

而不是.TargetControlID = targetDDL.ID我需要使用：

.TargetControlID = targetDDL.UniqueId

ASP CascadingDropDown控件导致IE脚本超时

1 个答案: