防止在文本框中输入非 ascii 字符

编程基础网 C#/.NET问题

2022-01-01

prevent typing non ascii characters in a textbox(防止在文本框中输入非 ascii 字符)

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问题描述

因为我认为人们在我之前已经遇到了很多时间，并且可能有一些标准的解决方案.. 任何人都可以给出任何提示方向如何防止用户在文本框中输入非 ascii 字符.

Since I think people have encounter it lots of time before I did and there may be some standart solution.. Can anybody give any hint direction how to prevent a user from typing non ascii characters in a textbox.

推荐答案

我个人觉得修改标准交互模式有点烦人，但是如果你必须过滤键盘输入，你可以通过拦截按键事件并取消那些你不想要的:

I personally find tinkering with standard modes of interaction a bit annoying, but if you must filter keyboard input, you can do it by intercepting key press events and canceling the ones that you don't want:

var allowed = /[a-zA-Z0-9]/; // etc.

window.onload = function () {
    var input = document.getElementById("test");

    input.onkeypress = function () {
        // Cross-browser
        var evt = arguments[0] || event;
        var char = String.fromCharCode(evt.which || evt.keyCode);

        // Is the key allowed?
        if (!allowed.test(char)) {
            // Cancel the original event
            evt.cancelBubble = true;
            return false;
        }
    }
};

而且使用 jQuery 更简洁漂亮:

And it's more concise and prettier with jQuery:

var allowed = /[a-zA-Z0-9]/; // etc.

$(function () {
    var input = document.getElementById("test");

    $("#input").keypress(function (e) {
        // Is the key allowed?
        if (!allowed.test(String.fromCharCode(e.keyCode || e.which))) {
            // Cancel the original event
            e.preventDefault();
            e.stopPropagation();
        }
    });
});

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