当页面上有2个下拉控件时，验证控件不起作用

Question

<asp:DropDownList ID="dropdwnpizza" AppendDataBoundItems="true" runat="server" OnLoad="dropdwnpizza_Load">
    <asp:ListItem Text="<Select One>" Value="" />
</asp:DropDownList>
<asp:RequiredFieldValidator ID="rfqdropdwnpizza" runat="server" InitialValue="" ControlToValidate="dropdwnpizza" ForeColor="Red" ErrorMessage="*"></asp:RequiredFieldValidator>
<br />

<asp:Label ID="pizzasize" Text="Pizza Size" runat="server"></asp:Label><br />
<asp:DropDownList ID="DropDwnsize" runat="server">
    <asp:ListItem Text="Select One" Value=""></asp:ListItem>
    <asp:ListItem Text="small" Value="small"></asp:ListItem>
    <asp:ListItem Text="medium" Value="medium"></asp:ListItem>
    <asp:ListItem Text="large" Value="large"></asp:ListItem>
    <asp:ListItem Text="Extra Large" Value="Extra Large"></asp:ListItem>
</asp:DropDownList>
<asp:RequiredFieldValidator ID="rfqpizzasize" runat="server" InitialValue="" ControlToValidate="pizzasize" ForeColor="Red" ErrorMessage="*"></asp:RequiredFieldValidator>

when i placed 2nd validation control having id=rfqpizzasize on aspx page,an occured Control 'pizzasize' referenced by the ControlToValidate property of 'rfqpizzasize' cannot be validated.

Answer 1

rfqpizzasize应该具有ControlToValidate="DropDwnsize"而不是ControlToValidate="pizzasize"