如何从JavaScript的下拉列表中获取选定的值 [英] How to get selected value from Dropdown list in JavaScript

问题描述

如何使用JavaScript从下拉列表中获取选定的值?我已经尝试了以下方法，但是它不起作用.

How can you get the selected value from drop down list using JavaScript? I have tried the following but it does not work.

var sel = document.getElementById('select1');
var sv = sel.options[sel.selectedIndex].value;
alert(sv);

推荐答案

对我来说很好.

我有以下HTML:

<div>
    <select id="select1">
        <option value="1">test1</option>
        <option value="2" selected="selected">test2</option>
        <option value="3">test3</option>
    </select>
    <br/>
    <button onClick="GetSelectedItem('select1');">Get Selected Item</button>
</div>

以及以下JavaScript:

And the following JavaScript:

function GetSelectedItem(el)
{
    var e = document.getElementById(el);
    var strSel = "The Value is: " + e.options[e.selectedIndex].value + " and text is: " + e.options[e.selectedIndex].text;
    alert(strSel);
}

查看，您正在使用正确的ID.如果您将其与ASP.NET一起使用，则ID在呈现时会更改.

See that you are using the right id. In case you are using it with ASP.NET, the id changes when rendered.

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