jquery判断RadioButtonList和RadioButton中是否有选中项示例

<pre class="html" name="code"> <%--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></pre>

<pre class="csharp" name="code"><%--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> 
</pre>