Question

我想更改下拉列表，每当我进行一些更改时，它都会自动回发并触发下拉列表中的selectedindexchanged事件。我有问题，它自动发回，但不记得我选择，它刷新我的页面和我选择的项目丢失。我想在没有AJAX调用的情况下这样做。但是，如果AJAX是唯一的选择，我愿意接受它。

<asp:DropDownList ID="ddlProjectEditor" CssClass="ddlProjectEditor" Autopostback="true"  runat="server" >
    </asp:DropDownList>

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
  If Not Page.IsPostBack Then
        Dim F As facility = utilities.lookForFacility
        'Option to add Project information in editor

        _config = CType(System.Configuration.ConfigurationManager.GetSection("editorConfigGroup/general"), f896EditorConfig.Config.General)


        If F IsNot Nothing Then
            Dim _facilityID As String = F.FacilityID
            Dim count As Integer = 0
            Dim facility As facility = FacilityManager.getFacility(_facilityID, True)
            Me.ddlProjectEditor.Items.Insert(count, New ListItem(F.CompanyName, F.FacilityID))

            'Me.ddlProjectEditor.SelectedIndex = 0
            'Me.ddlProjectEditor.ClearSelection()


            For Each memberFID As String In (From Rel In facility.Relationships Where Rel.numberType = "hllTeam" Or Rel.numberType = "hllOffice" Select Rel.storeNumber)
                count = count + 1
                Dim CompanyName = FacilityManager.getFacility(memberFID, True).CompanyName
                Me.ddlProjectEditor.Items.Insert(count, New ListItem(CompanyName, memberFID))
            Next
        End If
    End If


End Sub

Protected Sub ddlProjectEditor_SelectedIndexChanged2(ByVal sender As Object, ByVal e As EventArgs) Handles ddlProjectEditor.SelectedIndexChanged
        Dim selectedFacilityID = ddlProjectEditor.SelectedItem.Value 
'This event doesn't get triggered.

    End Sub

Answer 1

您必须检查page directive文件中的web.config，然后查看是否EnableViewState="false"。如果是这种情况，请将其更改为EnableViewState="true"

Answer 2

将ddlProjectEditor_SelectedIndexChanged2更改为Public并将OnSelectedIndexChanged =“ddlProjectEditor_SelectedIndexChanged2”添加到下拉列表标记中。

Dropdownlist Autopost back问题：记住选择

2 个答案: