JS简单操作select和dropdownlist实例

本文实例讲述了JS简单操作select和dropdownlist的方法。分享给大家供大家参考。具体实现方法如下：

一、js选中服务器控件select与dropdownlist

1. js操作服务器控件select

<select id="selectID" onchange="return showMessage()">

     <option value="0">==请选择==</option>

     <option value="1">是</option>

     <option value="2">否</option>

</select>


<script type="text/javascript" language="javascript">

  function showMessage() {

      if (document.getElementById("selectID").options[document.getElementById("selectID").selectedIndex].value == 1) {

   alert("你好，你选择了第 1 个");

   document.getElementById("txtContractName").setAttribute("enable",false);

      }

      else if (document.getElementById("selectID").options[document.getElementById("selectID").selectedIndex].value == 2) {

   alert("你好，你选择了第 2 个");

      }

  }

</script>
//js操作服务器控件dropdownlist

<asp:DropDownList ID="ddlFolder" runat="server" SkinID="ddlSkin" AutoPostBack="false" OnSelectedIndexChanged="ddlFolder_SelectedIndexChanged">    

        <asp:ListItem Value="0">选项0</asp:ListItem>   

   <asp:ListItem Value="1">选项1</asp:ListItem>  

</asp:DropDownList>    

<asp:DropDownList ID="ddlFolder" runat="server" SkinID="ddlSkin" AutoPostBack="false" OnSelectedIndexChanged="ddlFolder_SelectedIndexChanged"> 

  <asp:ListItem Value="0">选项0</asp:ListItem>

  <asp:ListItem Value="1">选项1</asp:ListItem> 

</asp:DropDownList>

JS代码：

document.getElementById("ddlFolder").value="0";//0为你要选中的项的value

2. 根据Text值设置选中某项

var DropDownListCurrencyNew =  document.getElementById("ddlFolder");

for(i = 0; i < DropDownListCurrencyNew.options.length; i++)

{

          if(DropDownListCurrencyNew.options[i].text == "选项0")    

           {

               DropDownListCurrencyNew.options[i].selected = true; 

          }

}

二、js读取DropDownList选中项的value和text

Value：

var selValue = document.getElementById("DropDownList1").options[document.getElementById("DropDownList1").selectedIndex].value;

Text：

var selText = document.getElementById("DropDownList1").options[document.getElementById("DropDownList1").selectedIndex].text;

希望本文所述对大家的js与.net程序设计有所帮助。