jQuery文本字段仅接受数字作为输入，这很好用，但是当我使用数字键盘时，它不起作用

Question

I want my JQuery code to only accept numbers as input in the textfield, this code is working well for me but soon discovered that if I used the numbers in my numpad it does not work. Any suggestions for this problem guys?

Here is my code:

<script type="text/javascript">
    $(".txtboxToFilterNum").keydown(function(event) {

        if (event.keyCode == 46 || event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 0 || event.keyCode == 13 || event.keyCode == 27) {
            // let it happen, don't do anything
        }
        else {
            // Ensure that it is a NUMBER and stop the keypress
            if (event.keyCode < 48 || event.keyCode > 57 ) {
                event.preventDefault(); 
            }   
        }
});
</script>

Answer 1

不要检查按下了哪个键，而是给出了哪个内容，这将更容易检查内容是否仅是数字，并且可以防止许多其他事情，例如使用带字母的复制和粘贴（我猜这不是在您指定的代码也是如此）

Answer 2

working sample

HTML

<input type="text" class="textfield" value="" id="extra7" name="extra7" onkeypress="return isNumber(event)" />

Javascript

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;
}