vue2.x directive - 限制input只能输入正整数

import Vue from ‘vue‘
//只对input生效
export default function (el) {
    var input = el;
    input.onkeyup = function (e) {
        if(input.value.length==1){
            input.value = input.value.replace(/[^1-9]/g,‘‘);
        }else{
            input.value = input.value.replace(/[^\d]/g, "");
        }
    };
}

import limitNum from ‘./directive/onlyNum‘

Vue.directive(‘limitNum‘, limitNum);