if you want to push to watching array for instance, you can copy this array, then push to this copy, and then assign this copy to your watching array back. this is very simple. // copy array which you want to watchlet copiedArray=this.originArray.slice(0)// push to this copycopied...
vue中使用watch函数,当数据改变时自动引发事件 本来我的需求是这样的,使用ElementUI的日期选择器,当日期选择器被更改时需要根据新日期来向服务器获取新数据,但是发现这个日期选择器没有change事件,后来终于发现vue有个watch函数就是用来干这个的。懒得写太多,直接贴段代码: 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
参数为被访问的对象 如vm.$watch("info",function(new, old){console.log("watch success")});, this.getter =function(obj){return obj.info};,在执行watcher的get方法中,将执行value = this.getter.call(vm, vm);,触发属性的get方法,添加该watcher至info属性对应的def对象中,如果需要深度监听,将...
如前面所示,我们已经在watch选项中设置了deep: true来确保深度监视数组的变化。 确保在修改数组或其项时触发视图的更新: Vue的响应式系统会确保当你修改数组或其项时,视图会自动更新。但是,如果你直接修改数组的长度(如使用length属性)或者通过索引直接设置项(如array[index] = newValue),可能不会触发视图更新。在...
Watch监听Array数组变化 监听对象: data(){ return{ objVal: { name:'obj', type:'obj' } } }, watch:{ objVal:{ handler(val,oldval){ }, deep:true, immediate:true } }, methods:{ changeObj(){ this.objVal.name ='newobj'; }
Vue watch 监听复杂对象变化,oldvalue 和 newValue 一致的解决办法,例如我们监听如下数据格式数组Array或者是对象Object格式的字段 data(){return{dataList:[{name:"里斯",age:18,sex:"男"},{
String、Number、Boolean、Array watch:{ // 方式一:函数体message1(newValue,oldValue){console.log('message1值变更')}, // 方式二:对象形式message2:{handle(newValue,oldValue){console.log("message2值变更")}}, // 方式三:函数名message3:'mes3Change'// 函数名},methods:{mes3Change(newValue,old...
{ reactive, watch, ref } from 'vue'export default {setup() {const array = ref([1, 2, 3]);const changeArr = () => {console.log('触发');array.value = [];}watch(array.value, (now, old) => {console.log(now, old); // 触发changeArr的时候,监听不到})return {array, change...
For watch, the old-value can be cached explicitly since it only has a unique return value. However, this workaround will be invalid if there are multiple read methods of the array in a effect. Member Justineo commented May 17, 2022 Your code literally mean "run console.log(arr.indexOf...
dep.depend()if(childOb){// key对应的val是Object,当val里面的key发生改变时// 即obj[key][key1]=xxx// 也会通知目前obj[key]收集的Watcher的更新childOb.dep.depend()if(Array.isArray(value)){ dependArray(value)} } }returnvalue},set:functionreactiveSetter(newVal){ ...