jquery判断RadioButtonList和RadioButton是否有选中项的例子

<%--Body 代码--%>
<div>
<asp:RadioButtonList ID="RadioButtonList1" runat="server">
<asp:ListItem Value="A">a</asp:ListItem>
<asp:ListItem Value="B">b</asp:ListItem>
</asp:RadioButtonList>
<asp:RadioButton ID="RadioButton1" GroupName="RBtn" Text="男" runat="server" checked="true" />
<asp:RadioButton ID="RadioButton2" GroupName="RBtn" Text="女" runat="server" />
<asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="Button1_ClientClick()"></asp:Button>
</div>

<%--Head 代码--%>
<script language="javascript" type="text/javascript" src="js/jquery-1.9.1.js"></script>
<script language="javascript" type="text/javascript">
function Button1_ClientClick()
{
alert($("input[name='RadioButtonList1']:checked").val()); // 若都没有选中，则弹出“undefined”，若有选中的，则弹出对应的 Value 值
if(document.getElementById("RadioButton1").checked==true) // 若RadioButton1被选中
{
alert($("#RadioButton1:checked").val()); //弹出 RadioButton1
alert($("#RadioButton2:checked").val()); //弹出 undefined
alert($("#RadioButton1:checked").val()=="RadioButton1"); //弹出 true
}
return false; //暂时不用传到后台
}
</script>