Vue3监听reactive对象中属性变化的方法

目录

• 1. 监听 reactive 对象的某个属性
• 2. 监听整个 reactive 对象并检查是哪一个属性发生了变化
• 3. 监听多个属性
• 4. 使用 toRefs 进行属性监听
• 总结

import { reactive, watch } from 'vue';

const state = reactive({
  name: 'John',
  age: 30,
  location: 'New York',
});

// 监听 name 属性的变化
watch(() => state.name, (newValue, oldValue) => {
  console.log(`Name changed from ${oldValue} to ${newValue}`);
});

import { reactive, watch } from 'vue';

const state = reactive({
  name: 'John',
  age: 30,
  location: 'New York',
});

// 监听整个对象的变化
watch(
  state,
  (newValue, oldValue) => {
    for (const key in newValue) {
      if (newValue[key] !== oldValue[key]) {
        console.log(`${key} changed from ${oldValue[key]} to ${newValue[key]}`);
      }
    }
  },
  { deep: true } // 深度监听
);

import { reactive, watch } from 'vue';

const state = reactive({
  name: 'John',
  age: 30,
  location: 'New York',
});

// 监听 name 和 age 属性的变化
watch(
  () => [state.name, state.age],
  ([newName, newAge], [oldName, oldAge]) => {
    if (newName !== oldName) {
      console.log(`Name changed from ${oldName} to ${newName}`);
    }
    if (newAge !== oldAge) {
      console.log(`Age changed from ${oldAge} to ${newAge}`);
    }
  }
);

import { reactive, toRefs, watch } from 'vue';

const state = reactive({
  name: 'John',
  age: 30,
  location: 'New York',
});

const { name, age } = toRefs(state);

// 监听 name 属性的变化
watch(name, (newValue, oldValue) => {
  console.log(`Name changed from ${oldValue} to ${newValue}`);
});

// 监听 age 属性的变化
watch(age, (newValue, oldValue) => {
  console.log(`Age changed from ${oldValue} to ${newValue}`);
});