高分,....在线等........解决马上结贴...........简单问题

Question

if(RadioButtonList.selectedItem.value==null)

Answer 1

不对啊,兄弟,-------------------------------------------------------------Compilation Error 
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. Compiler Error Message: BC30201: 需要表达式。Source Error:Line 17: <script runat="server">
Line 18: Sub tj_click(Src As Object, E As EventArgs)
Line 19: if test.selectedItem.value==null then
Line 20: response.Write("ok")
Line 21: else
 
Source File: H:\web\vote\test.aspx    Line: 19

Answer 2

if(RadioButtonList1.SelectedIndex == -1)
{
Response.Write("没有选中");

}
else
{
Response.Write("选中了");
}

Answer 3

http://lucky_elove.www1.dotnetplayground.com/ShowDetail.aspx?id=7AE7D20A-A5DA-4303-AC2D-32046BE4D086

Answer 4

RadioButtonList1.SelectedIndex表示选择项的索引,当没有选择项时其值为-1

Answer 5

<asp:RadioButtonList id="RadioButtonList1" runat="server"></asp:RadioButtonList>
<asp:RequiredFieldValidator ControlToValidate="RadioButtonList1" id="RequiredFieldValidator1" runat="server" ErrorMessage="还未选择"></asp:RequiredFieldValidator>