当前位置: 首页 > 网络学院 > 客户端脚本教程 > JavaScript > JavaScript onkeydown 事件

JavaScript
JS 介绍
JS 怎样使用
JS 在哪使用
JS 变量
JS If...Else
JS Switch
JS 操作符
JS Popup Boxes
JS 函数
JS For 循环
JS While 循环
JS Break 循环
JS For...In
JS 事件
JS Try...Catch
JS Throw
JS onerror
JS 特殊字符
JS Guidelines
JS 对象介绍

JavaScript onkeydown 事件


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-03-04   浏览: 739 ::
收藏到网摘: n/a

Definition and Usage
定义与用法

The onkeydown event occurs when a keyboard key is pressed.
当按下一个键盘按键时触发onkeydown事件

Syntax
语法

onkeydown="所要执行的脚本"

Parameter
参数
Description
注释
SomeJavaScriptCode
所要执行的脚本
Required. Specifies a JavaScript to be executed when the event occurs.
必选项。当事件触发时所要执行的脚本

Supported by the following HTML tags:
所支持的HTML标签:

<a>, <acronym>, <address>, <area>, <b>, <bdo>, <big>, <blockquote>, <body>, <button>, <caption>, <cite>, <code>, <dd>, <del>, <dfn>, <div>, <dt>, <em>, <fieldset>, <form>, <h1> to <h6>, <hr>, <i>, <input>, <kbd>, <label>, <legend>, <li>, <map>, <object>, <ol>, <p>, <pre>, <q>, <samp>, <select>, <small>, <span>, <strong>, <sub>, <sup>, <table>, <tbody>, <td>, <textarea>, <tfoot>, <th>, <thead>, <tr>, <tt>, <ul>, <var>

Supported by the following JavaScript objects:
所支持的JavaScript对象:

document, image, link, textarea


Tips and Notes
注意

Browser differences: Internet Explorer uses event.keyCode to retrieve the character that was pressed and Netscape/Firefox/Opera uses event.which.
不同浏览器:IE用event.keyCode来获取被按下的按键值,而NetScape/FireFox/Opera用的则是event.which


Example
实例

In this example the user cannot type numbers into the input field:
在下面的例子中,用户将无法向文本框内输入数字:

<html>
<body>
<script type="text/javascript">
function noNumbers(e)
{
var keynum
var keychar
var numcheck
if(window.event) // IE
{
keynum = e.keyCode
}
else if(e.which) // Netscape/Firefox/Opera
{
keynum = e.which
}
keychar = String.fromCharCode(keynum)
numcheck = /d/
return !numcheck.test(keychar)
}
</script>
<form>
<input type="text" onkeydown="return noNumbers(event)" />
</form>
</html>

The output of the code above will be:
输出结果为:



Try-It-Yourself Demos
互动演练

onkeydown
How to use onkeydown.
如何应用onkeydown

评论 (0) All

登陆 | 还没注册?