Vue 限制input输入 小数点后两位number

<div id="app">
    <input class=" " type="number" placeholder="请输入金额" v-model="withdrawAmount" @input="checkNumber(withdrawAmount)" />
    <div class="Login_submit numWarning" id="waringAlert" @click="withdrawBtn">提现</div>
</div>

let app = new Vue({
    el: '#app',
    data: {
    placeholder: '请输入数值',
    'walletAmount':'', 
  },
  methods: {
      //方法一：
       checkNumber:function(withdrawAmount){
        content.withdrawAmount= (withdrawAmount.match(/^\d*(\.?\d{0,2})/g)[0]) || null                  
    },
//提现按钮
    withdrawBtn:function(){
        var withdrawAmount =content.withdrawAmount;
        var walletAmount = content.walletAmount;
        var re = /^[0-9]+.?[0-9]*/
        if (!Number(withdrawAmount) || !re.test(withdrawAmount) || withdrawAmount == '' || withdrawAmount == undefined || withdrawAmount == null){ 
            mui.alert("请输入金额！")
                        return false;
                }
         if (Number(walletAmount) < Number(withdrawAmount)){
                    mui.alert("余额不足！")
                    return false;
                }
                saveUserNewWithdraw();
        }
  }
})

方法二：

                        var re = /^[0-9]+.?[0-9]*/;
                   if(!re.test(withdrawAmount)){
                         mui.alert("请输入正确的充值金额！"); 
                         return
                    }
                           //限制小数点后2位数
                    /* var index = String(withdrawAmount).indexOf('.');
                    if (index != -1) {
                        var arrStr = [];
                        arrStr = String(withdrawAmount).split('.');
                        if (arrStr[1] && arrStr[1].length > 2) {
                            content.withdrawAmount = String(withdrawAmount).substring(0, index + 3);
                            return;

                        }else{
                            content.withdrawAmount = withdrawAmount;
                        }
                    } else {
                        content.withdrawAmount = withdrawAmount;
                    } */

参考来自：https://blog.csdn.net/u013243347/article/details/81181058