ASP.net Vb.Net Label.Text 不更新

Question

在我的 VB.net ASP 应用程序中，我有一些 ASPTREEVIEW，其中在页面加载时有一个标签，我为其设置了一些值。单击任何行后，我捕获该值并将其分配给标签。

但突然之间，该标签值并未按所选值进行更新。就好像我通过调试值来检查它一样，值发生了变化，但是当我使用 Lable.text = chosen_value ... 它设置了值，但它实际上并没有在 html 页面上发生变化。 HTML 显示旧值。

会出现什么问题，我不明白。

Imports DevExpress
Imports DevExpress.Xpo
Imports DevExpress.Data
Imports DevExpress.Data.Filtering
Imports System.Data

Partial Class _Default
    Inherits System.Web.UI.Page

    Public testvar As Integer = 35

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim xpcol As New XPCollection(Of WCSOEE.WcsGCObject)
        Dim GCObj1 As WCSOEE.WcsGCObject
        Dim Filter1 As New DevExpress.XtraCharts.DataFilter
        Dim SelectedGCObject As WCSOEE.WcsGCObject
        Filter1.ColumnName = "Oid"
        Filter1.Condition = XtraCharts.DataFilterCondition.Equal

        Filter1.Value = Label2.Text
        If Label2.Text = "" Then
            Label2.Text = 10
        End If
        For Each Siris As DevExpress.XtraCharts.Series In WebChartControl1.Series
            '  WebChartControl1.Series(Siris.Name).DataFilters.Item(0).Value = CInt(Label2.Text)
        Next


        Dim masterKeyvalue As DevExpress.Web.ASPxTreeList.TreeListNode = ASPxTreeList1.FocusedNode
        If masterKeyvalue IsNot Nothing Then
            SelectedGCObject = masterKeyvalue.DataItem
        Else
            SelectedGCObject = xpcol.Object(31)
        End If

        ' MsgBox(SelectedGCObject.GCName)
        MsgBox(Label2.Text)

        If IsPostBack = False Then
            Label2.Text = calculatehours(SelectedGCObject.Oid)
        End If

    End Sub

    Protected Function calculatehours(Oid As Integer)
        xpocolLogAvailability.Session = DevExpress.Xpo.XpoDefault.Session
        Dim logavail As New XPCollection(Of WCSOEE.LogAvailability)
        Dim gcobjlist As New XPCollection(Of WCSOEE.WcsGCObject)
        gcobjlist.Filter = CriteriaOperator.Parse("[Oid]=?", Oid)
        Dim filter As CriteriaOperator
        Dim ds As New DataTable
        Dim Series As New DevExpress.XtraCharts.Series
        Dim Filter1 As New DevExpress.XtraCharts.DataFilter
        ' Label2.Text = Oid


        logavail.Filter = CriteriaOperator.Parse("GCObject.Oid=?", Oid)
        Filter1.ColumnName = "Oid"
        Filter1.Condition = XtraCharts.DataFilterCondition.Equal
        Filter1.Value = Oid
        Dim arr1(32) As Long
        'For i As Int16 = 1 To 32
        '    arr1(i) = 0
        'Next
        'For Each gcobj As WCSOEE.LogAvailability In logavail
        '    arr1(gcobj.Status) = arr1(gcobj.Status) + gcobj.Duration
        'Next= ""
        'ds.Columns.Add(New DataColumn("Name", System.Type.GetType("System.Int32")))



        For Each Siris As DevExpress.XtraCharts.Series In WebChartControl1.Series

            WebChartControl1.Series(Siris.Name).DataFilters.Item(0).Value = Oid

        Next
        WebChartControl1.RefreshData()

        'For i As Int16 = 1 To 32
        '    ds.Rows.Add(i, arr1(i))
        'Next

        'ASPxListBox1.DataSource = ds
        'ASPxListBox1.DataBind()
        Return Oid
    End Function

    Protected Sub ASPxTreeList1_CustomCallback(sender As Object, e As DevExpress.Web.ASPxTreeList.TreeListCustomCallbackEventArgs) Handles ASPxTreeList1.CustomCallback

    End Sub

    Protected Sub ASPxTreeList1_FocusedNodeChanged(sender As Object, e As System.EventArgs) Handles ASPxTreeList1.FocusedNodeChanged
        Dim masterKeyvalue As DevExpress.Web.ASPxTreeList.TreeListNode = ASPxTreeList1.FocusedNode
        Dim SelectedGCObject As WCSOEE.WcsGCObject = masterKeyvalue.DataItem
        ' MsgBox(SelectedGCObject.GCName)

        If IsPostBack Then
            Label2.Text = calculatehours(SelectedGCObject.Oid)

        End If

        MsgBox(IsPostBack)
        MsgBox(Label2.Text)


    End Sub
End Class

Answer 1

发布一些代码，这样我们就可以准确地看到你在做什么，到目前为止还没有看到任何东西，确保你在页面加载中有一个 If 语句，如果当前请求不是回发，则只应用标签文本，否则标签将在每次请求时都设置为此。

If Not IsPostBack() Then
   lblSomeLabel.Text = "Page load text"
End If