<mu-text-field v-model.number="weightNum" solo full-width ></mu-text-field>

watch: {
            //監(jiān)聽(tīng)用戶輸入的重量值
            //如果超過(guò)最大重量，彈出提示，并且將輸入框重量置于最大值
            //如果低于最小重量，彈出提示，并且將輸入框重量置于最小值
            weightNum(val){
                if(val<this.weightLimit.minWeight){
                    this.$toast.showWarn({message: 'You can only enter between ' +this.weightLimit.minWeight+ ' and ' +this.weightLimit.maxWeight});
                    this.$data.weightNum = this.weightLimit.minWeight;
                }
                else if(val>this.weightLimit.maxWeight){
                    this.$toast.showWarn({message: 'You can only enter between ' +this.weightLimit.minWeight+ ' and ' +this.weightLimit.maxWeight});
                    this.$data.weightNum = this.weightLimit.maxWeight;
                }
            }        
        },

this.$data.weightNum = this.weightLimit.minWeight;

this.weightNum = this.weightLimit.minWeight;

 <script type="text/javascript">
            var vm = new Vue({
                el: app01,
                data:{
                    a:'test',
                }
            })
            // 檢測(cè)數(shù)據(jù)'a'的改變，放數(shù)據(jù)改變時(shí)執(zhí)行
            vm.$watch('a', function(newval, oldval){
                console.log(newval, oldval);
            })
            vm.$data.a = 'wdc'
        </script>