vue封装useWatch hook支持停止监听和重启监听功能

import { watch, reactive } from 'vue';

export function useWatch(source, cb, options) {
  const state = reactive({
    stop: null
  });

  function start() {
    state.stop = watch(source, cb, options);
  }

  function stop() {
    state.stop();
    state.stop = null;
  }

  // 返回一个对象，包含start和stop方法
  return {
    start,
    stop
  };
}

使用：

<template>
  <div>
    <p>Message: {{ message }}</p>
    <button @click="changeMessage">Change Message</button>
    <button @click="stopWatching">Stop Watching</button>
    <button @click="startWatching">Start Watching</button>
  </div>
</template>

<script>
import { reactive } from 'vue';
import { useWatch } from './useWatch';

export default {
  setup() {
    const state = reactive({
      message: 'Hello World',
      watcher: null
    });

    // 使用自定义的useWatch Hook来监听message属性
    state.watcher = useWatch(
      () => state.message,
      (newValue, oldValue) => {
        console.log('Message changed:', newValue, oldValue);
      }
    );

    function changeMessage() {
      state.message = 'Hello Vue 3';
    }

    function stopWatching() {
      state.watcher.stop();
    }

    function startWatching() {
      state.watcher.start();
    }

    return {
      message: state.message,
      changeMessage,
      stopWatching,
      startWatching
    };
  }
};
</script>