Question

我还在学习jQuery，我在网上提到了一些教程。我从这个网站获得了我的代码并将其插入JSFiddle以尝试但它没有用：

http://www.leniel.net/2012/10/javascript-regex-jquery-to-match-only-english-characters-in-input-textbox.html#sthash.XQxbhteA.1FTBwPAJ.dpbs

HTML

<input id="mytextbox" style="width:300px" placeholder="Only English letters are allowed here...">

JS

$("#mytextbox").on("keypress", function(event) {

    // Disallow anything not matching the regex pattern (A to Z uppercase, a to z lowercase and white space)
    // For more on JavaScript Regular Expressions, look here: https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Regular_Expressions
    var englishAlphabetAndWhiteSpace = /[A-Za-z ]/g;

    // Retrieving the key from the char code passed in event.which
    // For more info on even.which, look here: http://stackoverflow.com/q/3050984/114029
    var key = String.fromCharCode(event.which);

    //alert(event.keyCode);

    // For the keyCodes, look here: http://stackoverflow.com/a/3781360/114029
    // keyCode == 8  is backspace
    // keyCode == 37 is left arrow
    // keyCode == 39 is right arrow
    // englishAlphabetAndWhiteSpace.test(key) does the matching, that is, test the key just typed against the regex pattern
    if (event.keyCode == 8 || event.keyCode == 37 || event.keyCode == 39 || englishAlphabetAndWhiteSpace.test(key)) {
        return true;
    }

    // If we got this far, just return false because a disallowed key was typed.
    return false;
});

$('#mytextbox').on("paste",function(e)
{
    e.preventDefault();
});

我使用的框架是 No-Library（纯JS），扩展名设置为 onload 。

然而，这个脚本似乎适用于我所提及的网站。我可以知道我做错了吗？是不是我没有包含一些jQuery库？

Answer 1

作为一个框架，你需要选择一个jQuery版本（例如 jQuery 2.1.0 ）而不是 No-Library（纯JS）。

如果不这样做，jQuery库将不会被加载，因此你的jQuery相关代码将不起作用。

Answer 2

您必须包含jquery文件并使用它

＆＃13;

$("#mytextbox").on("keypress", function(event) {

    // Disallow anything not matching the regex pattern (A to Z uppercase, a to z lowercase and white space)
    // For more on JavaScript Regular Expressions, look here: https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Regular_Expressions
    var englishAlphabetAndWhiteSpace = /[A-Za-z ]/g;

    // Retrieving the key from the char code passed in event.which
    // For more info on even.which, look here: http://stackoverflow.com/q/3050984/114029
    var key = String.fromCharCode(event.which);

    //alert(event.keyCode);

    // For the keyCodes, look here: http://stackoverflow.com/a/3781360/114029
    // keyCode == 8  is backspace
    // keyCode == 37 is left arrow
    // keyCode == 39 is right arrow
    // englishAlphabetAndWhiteSpace.test(key) does the matching, that is, test the key just typed against the regex pattern
    if (event.keyCode == 8 || event.keyCode == 37 || event.keyCode == 39 || englishAlphabetAndWhiteSpace.test(key)) {
        return true;
    }

    // If we got this far, just return false because a disallowed key was typed.
    return false;
});

$('#mytextbox').on("paste",function(e)
{
    e.preventDefault();
});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input id="mytextbox" style="width:300px" placeholder="Only English letters are allowed here...">

＆＃13;

Answer 3

在左上角的下拉列表中选择一个jQuery库，它应该可以正常工作，如下我的小提琴：

http://jsfiddle.net/Delorian/8b7trd6d/

(copied OP's code)

jQuery代码没有在JSFiddle中执行

3 个答案: