Js得到radiobuttonlist选中值的两种方式

<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="ajaxselect.OnmouseTitle.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
        <meta content="Microsoft Visual Studio .NET 7.1" name="GENERATOR">
        <meta content="C#" name="CODE_LANGUAGE">
        <meta content="JavaScript" name="vs_defaultClientScript">
        <meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
        <script language="javascript">

         function getvalue()
        {
        var b=document.all.rbtid.length
        var a=document.getElementById("rbtid").cells.length;
        //alert(b);结果为5
        //alert(a);结果为4
        //for(var i=0;i<b-1;i++)这样也行
        for(var i=0;i<a;i++)
        {
          var ss="rbtid_"+i;
          var aa=document.getElementById(ss).value;
          //if(eval('document.all.rbtid_'+i).checked==true) //这样也行 eval()函数能将数据符串转成js运行
          var bb=document.getElementById(ss);
          if(document.getElementById(ss).checked) //注意checked不能写成Checked,要不然不成功
           {
                  alert(aa);
                  break;
           }     
       
        }
        }

或者用第二种方法:

 //得到radiobuttonlist
      var vRbtid=document.getElementById("rbtid");
      
//得到所有radio
      var vRbtidList= vRbtid.getElementsByTagName("INPUT");
      
for(var i = 0;i<vRbtidList.length;i++)
      {
        
if(vRbtidList[i].checked)
        {
           
var text =vRbtid.cells[i].innerText;
           
var value=vRbtidList[i].value;
           alert(
"选中项的text值为"+text+",value值为"+value);
        }
      }

此方法中,RadioButtonList在客户端被看成成了table,通过getElementsByTagName("INPUT")方法获取它的所有子radio,然后循环每个radio,再通过cells获取radio的text值。
        </script>
    </HEAD>
    <body MS_POSITIONING="GridLayout">
        <form id="Form1" method="post" runat="server">
            <FONT face="宋体">
                <asp:radiobuttonlist id="rbtid" style="Z-INDEX: 101; LEFT: 8px; POSITION: absolute; TOP: 8px" runat="server"
                    Width="216px" Height="176px" name="rbtid">
                    <asp:ListItem Value="0">0</asp:ListItem>
                    <asp:ListItem Value="1" Selected>1</asp:ListItem>
                    <asp:ListItem Value="2">2</asp:ListItem>
                    <asp:ListItem Value="3">3</asp:ListItem>
                </asp:radiobuttonlist><INPUT style="Z-INDEX: 102; LEFT: 184px; POSITION: absolute; TOP: 256px" onclick="getvalue()"
                    type="button" value="Button"></FONT>
        </form>
    </body>
</HTML>

原文地址:https://www.cnblogs.com/seapub/p/2786399.html