$(document).on("keypress", ".classname", function(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;
});

$(document).ready(function()
{
    $("#textBoxId").bind("change",checkInput);
});

function checkInput()
{
    // check if $('#textBoxId').val() is under your constraints
    // then change its value, removing the last character
    // since this event will be called each time you
    // type a character
}

下面是一个使用jQuery UI小部件工厂的答案。您可以轻松地自定义允许的字符。

$('input').numberOnly({
    valid: "0123456789+-.$,"
});

这将允许数字、数字符号和美元金额。

$.widget('themex.numberOnly', {
    options: {
        valid : "0123456789",
        allow : [46,8,9,27,13,35,39],
        ctrl : [65],
        alt : [],
        extra : []
    },
    _create: function() {
        var self = this;

        self.element.keypress(function(event){
            if(self._codeInArray(event,self.options.allow) || self._codeInArray(event,self.options.extra))
            {
                return;
            }
            if(event.ctrlKey && self._codeInArray(event,self.options.ctrl))
            {
                return;
            }
            if(event.altKey && self._codeInArray(event,self.options.alt))
            {
                return;
            }
            if(!event.shiftKey && !event.altKey && !event.ctrlKey)
            {
                if(self.options.valid.indexOf(String.fromCharCode(event.keyCode)) != -1)
                {
                    return;
                }
            }
            event.preventDefault(); 
        });
    },

    _codeInArray : function(event,codes) {
        for(code in codes)
        {
            if(event.keyCode == codes[code])
            {
                return true;
            }
        }
        return false;
    }
});

这个jQuery代码可以过滤掉按住Shift, Ctrl或Alt时键入的字符。

$('#AmountText').keydown(function (e) {
    if (e.shiftKey || e.ctrlKey || e.altKey) { // if shift, ctrl or alt keys held down
        e.preventDefault();         // Prevent character input
    } else {
        var n = e.keyCode;
        if (!((n == 8)              // backspace
        || (n == 46)                // delete
        || (n >= 35 && n <= 40)     // arrow keys/home/end
        || (n >= 48 && n <= 57)     // numbers on keyboard
        || (n >= 96 && n <= 105))   // number on keypad
        ) {
            e.preventDefault();     // Prevent character input
        }
    }
});

这将在添加非数字字符时保持先前的值。

$(document).on('input', '.digit-input', function() {
    var prevVal = $(this).attr('ov') ? $(this).attr('ov') : '';
    var newVal = this.value.replace(/[^0-9]/g, '');
    this.value = newVal != '' ? newVal : prevVal;
    $(this).attr('ov', this.value);
});

$(文件)。据(’input’'。digit-input'，函数(){ var prevVal = $(this).attr('ov') ?$(this).attr('ov'): "; var newVal = this.value。回想起(^ [0 - 9]/ g '); this。= = " ? "newVal: prevVal; $ (this)。attr(’ov’this.value); }); < script " src = " https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js " > / < script > <input type="text" class=" digital -input">

重构了已接受的答案，因此不再需要使用注释，因为我讨厌注释。这也更容易用茉莉花进行测试。

    allowBackspaceDeleteTabEscapeEnterPress: function(event){
    return ($.inArray(event.keyCode, [46, 8, 9, 27, 13, 190]) >= 0);
},
allowContorlAPress: function(event){
    return (event.keyCode == 65 && event.ctrlKey === true)
},
allowHomeEndLeftRightPress: function(event){
    return (event.keyCode >= 35 && event.keyCode <= 39)
},
theKeyPressedIsEditRelated: function (event) {
    return (this.allowBackspaceDeleteTabEscapeEnterPress(event)
            || this.allowContorlAPress(event)
            || this.allowHomeEndLeftRightPress(event));
},
isNotFromTheNumKeyPad: function (event) {
    return (event.keyCode < 96 || event.keyCode > 105);
},
isNotFromTopRowNumberKeys: function (event) {
    return (event.keyCode < 48 || event.keyCode > 57);
},
theKeyIsNonNumeric: function (event) {
   return (event.shiftKey
           || (this.isNotFromTopRowNumberKeys(event)
                && this.isNotFromTheNumKeyPad(event)));
},
bindInputValidator: function(){
    $('.myinputclassselector').keydown(function (event) {
        if(this.validateKeyPressEvent(event)) return false;
    });
},
validateKeyPressEvent: function(event){
    if(this.theKeyPressedIsEditRelated(event)){
        return;
    } else {
        if (this.theKeyIsNonNumeric(event)) {
            event.preventDefault();
        }
    }
}