javascript - 在 SelectOneMenu 框中获取选定的值

Question

此语句没有给我在 selectonemenu 框中选择的值：

document.getElementById("purchaseOrderForm:supplierName").value;

怎么做？

Answer 1

似乎对我有用

<form>
    <select id="purchaseOrderForm:supplierName">
        <option value="value 1">value 1 </option>
        <option value="value 2">value 2 </option>
        <option value="value 3">value 3 </option>
    </select>
   <input type="button" id="btn_showValue" value="show value"/>
</form>

document.getElementById("btn_showValue").onclick = function(){
  console.log(document.getElementById("purchaseOrderForm:supplierName").value)
}

http://jsfiddle.net/wLrLg/1/

Answer 2

您可以尝试以下方法。例子

HTML

<form>
    <select id="purchaseOrderForm:supplierName">
        <option value="1">Order 1 </option>
        <option value="2">Order 2 </option>
        <option value="3">Order 3 </option>
    </select>
   <input type="button" id="submit" value="submit" onclick="getvalue();"/>
</form>

Javascript

function getvalue()
{
var e = document.getElementById("purchaseOrderForm:supplierName");
var str = e.options[e.selectedIndex].value; //the value of the selected option
alert(str);

var e = document.getElementById("purchaseOrderForm:supplierName");
var str = e.options[e.selectedIndex].text; //the text of the selected option
alert(str);
}