正则校验金额 0-2位

 <el-form :rules="rules" :model="balanceRecharge" ref="form">
        <el-form-item label="充值金额" prop="rechargeAmount">
              <el-input placeholder="请输入金额" v-model="balanceRecharge.rechargeAmount">
                   <template slot="append">元</template>
               </el-input>
         </el-form-item>
 </el-form>
   export default {
    data () {
        // 金额验证
        let validateAmount = (rule, value, callback) => {
            if (value) {
                // let reg = /^[1-9]*[1-9][0-9]*$/;
                let reg = /^(([1-9]{1}\d*)|(0{1}))(\.\d{0,2})$/;
                if (!reg.test(value)) {
                    callback(new Error('请输入正确的金额!'));
                } else {
                    callback();
                }
            } else {
                callback(new Error('请输入正确的金额!'));
            }
        };
        return {
            balanceRecharge: {
                rechargeAmount: 0,
            },
            rules: {
                rechargeAmount: [
                    { validator: validateAmount, trigger: ['blur', 'change'], required: true }
                ]
            }
        };
    },