html< input type =" text" /> onchange事件不起作用 [英] html <input type="text" /> onchange event not working

问题描述

我正在尝试做一些实验。我想要发生的是，每次用户在文本框中键入内容时，它都会显示在对话框中。我使用 onchange 事件属性来实现它，但它不起作用。我仍然需要按下提交按钮才能使其正常工作。我读到了关于AJAX的内容，我正在考虑了解这一点。我是否仍然需要AJAX才能使其工作或简单的JavaScript足够？请帮忙。

I am trying to do some experiment. What I want to happen is that everytime the user types in something in the textbox, it will be displayed in a dialog box. I used the onchange event property to make it happen but it doesn't work. I still need to press the submit button to make it work. I read about AJAX and I am thinking to learn about this. Do I still need AJAX to make it work or is simple JavaScript enough? Please help.

index.php

<script type="text/javascript" src="javascript.js"> </script>

<form action="index.php" method="get">
 Integer 1: <input type="text" id="num1" name="num1" onchange="checkInput('num1');" /> <br />
 Integer 2: <input type="text" id="num2" name="num2" onchange="checkInput('num2');" /> <br />
 <input type="submit" value="Compute" />
</form>

javascript.js

function checkInput(textbox) {
 var textInput = document.getElementById(textbox).value;

 alert(textInput); 
}

推荐答案

onchange 仅在控件模糊时触发。请尝试 onkeypress 。

onchange is only triggered when the control is blurred. Try onkeypress instead.

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