摘要：小數點限制兩位小數正整數限定為正整數動態添加了內容要用事件委托方式綁定下面的事件保留至多兩個小數點的數字顯示效果說明適用于多種情況判斷

HTML

    
    
    
    
    
    
    



    

    

        

            

                兩位小數：
                正整數：
            
        
    
    
    
     
    

JS

function amountInput(parent,child) {
    var CashingAmountLast = "";

    $moneyInput = ""; //動態添加了內容  要用事件委托方式綁定下面的事件

    function checkCode(code) {
        var codeArea = code > 57 && code < 96;
        if (!(code == 190 || code == 110 || code == 46 || code == 8 || code == 37 || code == 39)) {
            if (codeArea || code < 48 || code > 105) {
                return false;
            }
        }
        return true;
    }
    
    $(parent).on("keydown", child, function(e) {
        var code = e.keyCode,
            val = e.target.value;
        if (val.indexOf(".") > -1 && (code == 190 || code == 110)) {
            e.target.value = val;
            return false;
        }
        if (!checkCode(code)) {
            return false;
        }
        this.setAttribute("data-keyCode", code);
        return true;
    }).on("input",child, function(e) {
        var val = this.value,
            keyCode = this.getAttribute("data-keyCode"),
            reSet = false;
        if (e.currentTarget.validity.valid) {
            if (val.indexOf(".") < 0 && (keyCode == 190 || keyCode == 110)) {
                val += ".";
            }
        } else {
            val = CashingAmountLast;
            if ((keyCode == 190 || keyCode == 110) && val.indexOf(".") < 0) {
                val = Number(CashingAmountLast).toFixed(1);
            }
            reSet = true;
        }
        fixCashFn.call(this,val, reSet);
    }).on("blur", child,function(e) {
        var val = Number($(this).val());
        if (!isNaN(val)) {
            e.target.value = val;
        } else {
            e.target.value = 0;
        }
    });

    function fixCashFn(a, isReset) {
        let money = typeof a === "string" ? a : a.toString(),
            flag = false,
            valArr = [],
            _slef = this;
        money = money.replace(/s/g, "");
        var strLen = money.length;
        if (isNaN(Number(money))) {
            flag = true;
        } else if (strLen > 0) {
            //保留至多兩個小數點的數字
            if (!/^d+(?:.d{1,2})?$/.test(money) && money.charAt(strLen - 1) !== ".") {
                flag = true;
            }
        }
        if (flag) {
            money = CashingAmountLast;
        }
        if (isNaN(Number(money))) {
            money = "";
        }
        (function() {
            if (money.length > 0) {
                valArr = money.split(".");
                money = Number(valArr[0]).toString().slice(0, 10);
                if (valArr.length > 1) {
                    money += "." + valArr[1].slice(0, 2);
                }
            }
            if (money.charAt(money.length - 1) !== ".") {
                if (a !== money) {
                    $(_slef).val(money);
                    CashingAmountLast = money;
                } else {
                    CashingAmountLast = a;
                }
            }
            if (isReset) {
                $(_slef).val(money);
            }
        })();
    }
}

顯示效果

說明
適用于多種情況判斷