无法在AJAX响应中获取HTML select的值

Question

There are two steps on my code. 我的代码有两个步骤。 First step a user fills some fields and then data is submitted by ajax to server. 第一步，用户填写一些字段，然后将数据由Ajax提交到服务器。 Ajax returns a HTML select input that user must choose a value. Ajax返回一个HTML选择输入，用户必须选择一个值。 This is the second step. 这是第二步。

The problem is, when I try to get the value of select in javascript, it shows me null. 问题是，当我尝试获取javascript中select的值时，显示为null。

The code I use to get select value works in normal situation. 我用来获取选择值的代码在正常情况下有效。 But when select is retrieved by ajax, this problem occurs. 但是当用ajax检索select时，就会出现此问题。

Code to get select value 获取选择值的代码

var e = document.getElementById("ordernum");
var num = e.options[e.selectedIndex].value;

Answer 1

Here's an example HTML file showing how to dynamically generate a select element and get the value back from it on its onchange event via event.target.value: 这是一个示例HTML文件，该文件显示了如何动态生成select元素并通过event.target.value在其onchange事件上从中获取值：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <script>
            const GameDifficulty = {
                EASY:1,
                MEDIUM:2,
                HARD:3,
                INSANE:4
            };

            function init(event) {
                console.log(event);
                var body = document.getElementById('body');
                var select = document.createElement('select');
                select.id = 'selDifficulty';
                for (var diff in GameDifficulty) {
                    var option = document.createElement('option');
                    option.value = GameDifficulty[diff];
                    option.innerHTML = diff;
                    select.appendChild(option);
                }

                select.onchange = test;

                body.appendChild(select);
                console.log(body);
            }

            function test(event) {
                console.log(event.target.value);
            }

            window.onload = init;
        </script>
    </head>
    <body id="body">
    </body>
</html>

无法在AJAX响应中获取HTML select的值

问题描述

1 个解决方案

解决方案1
0 已采纳 2016-08-02 15:04:05

无法在AJAX响应中获取HTML select的值

问题描述

1 个解决方案

解决方案1 0 已采纳 2016-08-02 15:04:05

解决方案1
0 已采纳 2016-08-02 15:04:05