RequiredFieldValidator验证下拉列表框

 

< asp:DropDownList  ID ="DropDownList1"  runat ="server"  CssClass ="style01" >
        < asp:ListItem  Text ="请选择"  Value ="" ></ asp:ListItem >
</ asp:DropDownList >
< asp:Label  ID ="Label10"  runat ="server"  Text ="*"  ForeColor ="Red"  Font-Size ="Smaller" ></ asp:Label >
< asp:RequiredFieldValidator  ID ="RequiredFieldValidator1"  runat ="server"  ControlToValidate ="DropDownList1"  InitialValue =""  ErrorMessage ="请选择信息"  Font-Size ="Smaller"  ForeColor ="Red" ></ asp:RequiredFieldValidator >