按键事件的addEventListener中的问题……仅用于限制输入字符
[英]problem in addEventListener for keypress event… for restricting the input charcters only
问题描述
I have placed one textbox.... I want to put restriction on it .. 
我已经放置了一个文本框..我想对其进行限制..
that digits and special characters should not be allowed to input in textbox... 不允许在文本框中输入数字和特殊字符...
how can i do using onkeypress event in Javascript ??? 我该如何在Javascript中使用onkeypress事件？
my code is ... 我的代码是...
<script>
function event()
{
document.getElementById("TX1").addEventListener("keypress", handleKeyPress, false);
}
function handleKeyPress(e)
{
var restricted = "0123456789_#!";
var key = e.keyCode || e.which;
var i=0;
for(;i<restricted.length;i++)
{
if (restricted.charCodeAt(i) == key)
{
e.returnValue = false;
}
return true;
}
</script>
<body onLoad="event();">
<input type="text" name="T1" id="TX1" size="27" maxlength="35" >
</body>
2 个解决方案
解决方案1
5 2011-03-13 10:47:40
that digits and special characters should not be allowed to input in textbox...
Don't do this through keypress filtering. 不要通过keypress过滤来做到这一点。 It's user-hostile, confusing, messes up other control keypresses and is easy to defeat by using other methods of input, such as copy/paste, drag/drop, form fillers, spellcheckers, IMEs... 它对用户不利，令人困惑，使其他控制键混乱，并且易于通过使用其他输入方法来克服，例如复制/粘贴，拖放/填充，表格填充，拼写检查，IME等。
Instead, have a warning that visibly directs the user when they've put something unexpected in, eg.: 相反，当用户放置了意外内容时，应发出警告以明显指导用户，例如：
<input type="text" name="T1" id="TX1"/>
<div id="TX1_help">
Please do not use numbers or ‘!’, ‘_’ or ‘#’ characters in this field.
</div>
<script type="text/javascript">
var tx1= document.getElementById('TX1');
var tx1help= document.getElementById('TX1_help');
function checkTX1() {
var isok= /^[^0-9_#!]*$/.test(tx1.value);
tx1help.style.display= isok? 'none' : 'block';
}
checkTX1();
// Re-check the field every time a key is pressed or other change event.
// To ensure it is still checked in a timely fashion in the case of
// non-keyboard events, add a timer as well.
//
tx1.onchange=tx1.onkeyup= checkTX1;
setInterval(checkTX1, 500);
</script>
You can use addEventListener for the event attachment if you want to, but be aware this won't work in IE<9, for which you would need the attachEvent model. 如果需要，可以将addEventListener用作事件附件，但是请注意，这在IE <9中将不起作用，为此，您需要attachEvent模型。 ( event.returnValue is specific to the IE attachEvent model and will not work with addEventListener , which uses event.preventDefault() instead.) （ event.returnValue特定于IE attachEvent模型，不适用于addEventListener ，后者使用event.preventDefault()代替。）
解决方案2
0 2014-08-01 12:16:46
Try the following: 请尝试以下操作：
document.getElementById('TX1').addEventListener('keypress', function(event) {
if (event.keyCode == 13) {
handleKeyPress();
}
});
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