Question

如果在第一个下拉框中选择了手机，我想关闭下拉PhoneHelp，但它似乎不起作用。这是代码：

达网络

        <asp:DropDownList ID="ddlHowRec" runat="server">
            <asp:ListItem Value="" Text="Choose an option"></asp:ListItem>
            <asp:ListItem Value="mail" Text="Mail"></asp:ListItem>
            <asp:ListItem Value="e-mail" Text="E-mail"></asp:ListItem>
            <asp:ListItem Value="phone" Text="Call back"></asp:ListItem>
        </asp:DropDownList>


            <asp:Label ID="lblPhoneHelp" runat="server" AssociatedControlID="ddlPhoneHelp"></asp:Label>
        <asp:DropDownList ID="ddlPhoneHelp" runat="server">
            <asp:ListItem Value="" Text="Choose an option"></asp:ListItem>
            <asp:ListItem Value="yes" Text="Yes"></asp:ListItem>
            <asp:ListItem Value="no" Text="No"></asp:ListItem>
        </asp:DropDownList>

VB：

    Protected Sub ddlHowRec_SelectedIndexChanged(ByVal sender As Object, ByVal e As      System.EventArgs) Handles ddlHowRec.SelectedIndexChanged

    If ddlHowRec.SelectedValue = "phone" Then
        lblPhoneHelp.Enabled = False
    Else
        lblPhoneHelp.Enabled = True
    End If
 End Sub

谢谢

Answer 1

您正在停用lblPhoneHelp而不是ddlPhoneHelp。

ddlPhoneHelp.Enabled = Not ddlHowRec.SelectedValue = "phone"

更新面板无法正常工作，不确定原因

1 个答案: