c# - 'System.Web.UI.WebControls.ListItemCollection' 中不允许使用文字内容 ('')

Question

我面临以下错误：

Literal content ('</asp:RequiredFieldValidator>') is not allowed within a 'System.Web.UI.WebControls.ListItemCollection' 

对于以下代码（在 customer.ascx 中）：

<div class="customerTableRow">
    <div class="customerTableLeftCol">
        <asp:Label ID="CustomerCountryLabel" runat="server" Text="Country:"></asp:Label>
    </div>
    <div class="customerTableRightCol">
        <asp:DropDownList ID="CustomerCountryDropDownList" runat="server">
            <asp:RequiredFieldValidator ID="CustomerCountryRequiredFieldValidator" ControlToValidate="CustomerCountryDropDownList" runat="server" ErrorMessage="RequiredFieldValidator">
            </asp:RequiredFieldValidator>
        </asp:DropDownList>
    </div>
</div>

我错过了什么吗？

Answer 1

将 RequiredFieldValidator 移出 DropDownList

<div class="customerTableRow">
    <div class="customerTableLeftCol">
        <asp:Label ID="CustomerCountryLabel" runat="server" Text="Country:"></asp:Label>
    </div>
    <div class="customerTableRightCol">
        <asp:DropDownList ID="CustomerCountryDropDownList" runat="server">
        </asp:DropDownList>


            <asp:RequiredFieldValidator ID="CustomerCountryRequiredFieldValidator" ControlToValidate="CustomerCountryDropDownList" runat="server" ErrorMessage="RequiredFieldValidator">
            </asp:RequiredFieldValidator>
    </div>
</div>