<el-button type="primary" plain round @click="stop">stop</el-button>

const stop = watchEffect((onInvalidate) => {
  console.log(massage.value);
  onInvalidate(()=>{
  console.log('2');  //這個回先執(zhí)行，log 2,然后log massage.value

}),{

flush:'post'，

 onTrack?: (event: DebuggerEvent) => void  調(diào)試bug用
  onTrigger?: (event: DebuggerEvent) => void

} }) flush:'post' //添加flush:'post' 組件更新后執(zhí)行對應方法，sync 強制效果始終同步觸發(fā)   pre組件更新前執(zhí)行