vue限制输入框只能输入8位整数和2位小数的代码

----代码省略
<input id="amt" type="number" v-model="amount"/>
----代码省略
data:{
 return{
  amount:""
 }
}
----代码省略
watch:{
 amount(newVal,oldVal){
 console.log(newVal)
 var reg = /^(\d{0,8})(\.(\d{0,2}))?$/g;
 if(!reg.test(newVal)){
  if(newVal == ''){
 this.amount = '';
 return;
  }
  this.amount = oldVal
 }else{
  this.amount = newVal;
 }
 }
}

<input type="text" placeholder="请输入金额" v-model="orderMoney" @input="checkInput" />

checkInput() {
 this.orderMoney = this.dealInputVal(this.orderMoney);
},
dealInputVal(value) {
  value = value.replace(/^0*(0\.|[1-9])/, "$1");
  value = value.replace(/[^\d.]/g, ""); //清除"数字"和"."以外的字符
  value = value.replace(/^\./g, ""); //验证第一个字符是数字而不是字符
  value = value.replace(/\.{1,}/g, "."); //只保留第一个.清除多余的
  value = value
   .replace(".", "$#$")
   .replace(/\./g, "")
   .replace("$#$", ".");
  value = value.replace(/^(\-)*(\d*)\.(\d\d).*$/, "$1$2.$3"); //只能输入两个小数
  value =
   value.indexOf(".") > 0
    ? value.split(".")[0].substring(0, 10) + "." + value.split(".")[1]
    : value.substring(0, 10);
  return value;
 }