Javascript 只允许在文本框中输入数字
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Allow only numbers to be typed in a textbox
提问by EnexoOnoma
How to allow only numbers to be written in this textbox ?
如何只允许在此文本框中写入数字？
<input type="text" class="textfield" value="" id="extra7" name="extra7">
回答by Darin Dimitrov
You could subscribe for the onkeypress event:
您可以订阅 onkeypress 事件：
<input type="text" class="textfield" value="" id="extra7" name="extra7" onkeypress="return isNumber(event)" />
and then define the isNumberfunction:
然后定义isNumber函数：
function isNumber(evt) {
evt = (evt) ? evt : window.event;
var charCode = (evt.which) ? evt.which : evt.keyCode;
if (charCode > 31 && (charCode < 48 || charCode > 57)) {
return false;
}
return true;
}
You can see it in action here.
回答by powtac
With HTML5 you can do
使用 HTML5，您可以做到
<input type="number">
You can also use a regex pattern to limit the input text.
您还可以使用正则表达式模式来限制输入文本。
<input type="text" pattern="^[0-9]*$" />
回答by Arnout Engelen
You also can use some HTML5 attributes, some browsers might already take advantage of them (type="number" min="0").
您还可以使用一些 HTML5 属性，某些浏览器可能已经利用了它们 ( type="number" min="0")。
Whatever you do, remember to re-check your inputs on the server side: you can never assume the client-side validation has been performed.
无论您做什么，请记住在服务器端重新检查您的输入：您永远不能假设已经执行了客户端验证。
