你可以使用一个简单的JavaScript正则表达式来测试纯数字字符:

/^[0-9]+$/.test(input);

如果输入是数字，则返回true，否则返回false。

或事件键码，简单使用如下:

     // Allow: backspace, delete, tab, escape, enter, ctrl+A and .
    if ($.inArray(e.keyCode, [46, 8, 9, 27, 13, 110, 190]) !== -1 ||
         // Allow: Ctrl+A
        (e.keyCode == 65 && e.ctrlKey === true) || 
         // Allow: home, end, left, right
        (e.keyCode >= 35 && e.keyCode <= 39)) {
             // let it happen, don't do anything
             return;
    }

    var charValue = String.fromCharCode(e.keyCode)
        , valid = /^[0-9]+$/.test(charValue);

    if (!valid) {
        e.preventDefault();
    }

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();
        }
    }
}

我想帮点忙，我做了我的版本，onlyNumbers函数…

function onlyNumbers(e){
    var keynum;
    var keychar;

    if(window.event){  //IE
        keynum = e.keyCode;
    }
    if(e.which){ //Netscape/Firefox/Opera
        keynum = e.which;
    }
    if((keynum == 8 || keynum == 9 || keynum == 46 || (keynum >= 35 && keynum <= 40) ||
       (event.keyCode >= 96 && event.keyCode <= 105)))return true;

    if(keynum == 110 || keynum == 190){
        var checkdot=document.getElementById('price').value;
        var i=0;
        for(i=0;i<checkdot.length;i++){
            if(checkdot[i]=='.')return false;
        }
        if(checkdot.length==0)document.getElementById('price').value='0';
        return true;
    }
    keychar = String.fromCharCode(keynum);

    return !isNaN(keychar);
}

只需添加输入标签“…输入……id="price" onkeydown="return onlyNumbers(event)"…"然后你就完成了;)

你可以使用这个JavaScript函数:

function maskInput(e) {
    //check if we have "e" or "window.event" and use them as "event"
        //Firefox doesn't have window.event 
    var event = e || window.event 

    var key_code = event.keyCode;
    var oElement = e ? e.target : window.event.srcElement;
    if (!event.shiftKey && !event.ctrlKey && !event.altKey) {
        if ((key_code > 47 && key_code < 58) ||
            (key_code > 95 && key_code < 106)) {

            if (key_code > 95)
                 key_code -= (95-47);
            oElement.value = oElement.value;
        } else if(key_code == 8) {
            oElement.value = oElement.value;
        } else if(key_code != 9) {
            event.returnValue = false;
        }
    }
}

你可以像这样把它绑定到你的文本框:

$(document).ready(function() {
    $('#myTextbox').keydown(maskInput);
});

我在生产中使用了上面的方法，它工作得很好，而且是跨浏览器的。此外，它不依赖于jQuery，所以你可以用内联JavaScript将它绑定到你的文本框:

<input type="text" name="aNumberField" onkeydown="javascript:maskInput()"/>

我建议检查事件。我也带着。如果设置为true，用户可能会执行类似cmd-A的操作来选择字段中的所有文本。你也应该承认这一点。

jQuery("#no_of").keypress(function(event){
    //Allow only backspace and delete
    if (event.keyCode != 46 && event.keyCode != 8) {
        if (!parseInt(String.fromCharCode(event.which))) {
            event.preventDefault();
        }
    }
});

jQuery("#no_of").keyup(function(e){
    var temp_s= jQuery("#no_of").val();
    var multiply_val= temp_s*10;
    jQuery("#ex-r").html(multiply_val);
});