Asp.net 如何在DetailsView中引用DropDownList？

我有一个DetailsView，其中包含几个文本框和一个下拉列表

现在，我想做的是为DropDownList编写SelectedIndexChanged事件，但我的问题是我无法再访问/引用它

如果我只是在表单上放一个下拉列表，这没问题，但现在它在Details视图中，似乎不可能找到它

有什么建议吗

Imports System
Imports System.Web.UI
Imports System.Web.UI.WebControls

Protected Sub DetailsViewAvtaleInfo_PageIndexChanging1(sender As Object, e As DetailsViewPageEventArgs) Handles DetailsViewAvtaleInfo.PageIndexChanging

    Dim DropDownListContractType As DropDownList = DirectCast(Me.DetailsViewAvtaleInfo.FindControl("DropDownListContractType"), DropDownList)
    Dim TextBoxLeasingPriceMonth As TextBox = DirectCast(Me.DetailsViewAvtaleInfo.FindControl("TextBoxLeasingPriceMonth"), TextBox)

    If DropDownListContractType.Text = "Kjøp" Then
        TextBoxLeasingPriceMonth.Visible = False
    End If

End Sub

我知道这是不对的，但就我所知。我只想在以下子系统中编写代码，但它无法工作：

    Protected Sub DropDownListContractType_SelectedIndexChanged(sender As Object, e As EventArgs)      Handles DropDownListContractType.SelectedIndexChanged
    Dim TextBoxLeasingPriceMonth As TextBox = DirectCast(Me.DetailsViewAvtaleInfo.FindControl("TextBoxLeasingPriceMonth"), TextBox)

    If DropDownListContractType.Text = "Leasing" Then
        TextBoxLeasingPriceMonth.Visible = False
    End If
End Sub 

---

您没有发布dropdownlist的标记，它应该如下所示（将方法附加到事件）：

<asp:DropDownList ID="DropDownListContractType" AutoPostBack="true"  runat="server" OnSelectedIndexChanged="DropDownListContractType_SelectedIndexChanged">                        
    <asp:ListItem Text="Kjøp" Value="2"></asp:ListItem>
    <asp:ListItem Text="Leasing" Value="1"></asp:ListItem>
</asp:DropDownList>

我已经测试了上面的代码。如果您有任何问题，请尝试复制/粘贴标记和代码

您可以下载我的测试项目与您的进行比较。

“…但它不会工作”-更具体一些。它是在第一段代码中看到您的下拉列表，还是仅在第二段代码中看到您的下拉列表？为什么不使用FindControl（）获取下拉列表？

Protected Sub DropDownListContractType_SelectedIndexChanged(sender As Object, e As EventArgs)
    Dim DropDownListContractType As DropDownList = DirectCast(sender, DropDownList)
    Dim TextBoxLeasingPriceMonth As TextBox = DirectCast(DropDownListContractType.NamingContainer.FindControl("TextBoxLeasingPriceMonth"), TextBox)

    If DropDownListContractType.SelectedItem.Text = "Leasing" Then
        TextBoxLeasingPriceMonth.Visible = False
    End If
End Sub


Protected Sub DetailsViewAvtaleInfo_PageIndexChanging(sender As Object, e As DetailsViewPageEventArgs) Handles DetailsViewAvtaleInfo.PageIndexChanging
    Dim DropDownListContractType As DropDownList = DirectCast(Me.DetailsViewAvtaleInfo.FindControl("DropDownListContractType"), DropDownList)
    Dim TextBoxLeasingPriceMonth As TextBox = DirectCast(Me.DetailsViewAvtaleInfo.FindControl("TextBoxLeasingPriceMonth"), TextBox)

    If DropDownListContractType.SelectedItem.Text = "Kjøp" Then
        TextBoxLeasingPriceMonth.Visible = False
    End If
End Sub