下面是一种为嵌套属性编写观察者的方法:

    new Vue({
        ...allYourOtherStuff,
        watch: {
            ['foo.bar'](newValue, oldValue) {
                // Do stuff here
            }
        }
    });

你甚至可以对异步观察者使用这个语法:

    new Vue({
        ...allYourOtherStuff,
        watch: {
            async ['foo.bar'](newValue, oldValue) {
                // Do stuff here
            }
        }
    });

下面是一种为嵌套属性编写观察者的方法:

    new Vue({
        ...allYourOtherStuff,
        watch: {
            ['foo.bar'](newValue, oldValue) {
                // Do stuff here
            }
        }
    });

你甚至可以对异步观察者使用这个语法:

    new Vue({
        ...allYourOtherStuff,
        watch: {
            async ['foo.bar'](newValue, oldValue) {
                // Do stuff here
            }
        }
    });

你可以使用深层观察者:

watch: {
  item: {
     handler(val){
       // do stuff
     },
     deep: true
  }
}

现在它将检测对项目数组中对象的任何更改以及对数组本身的添加(当与Vue.set一起使用时)。这是一个JSFiddle: http://jsfiddle.net/je2rw3rs/

EDIT

如果你不想观察顶层对象的每一个变化，只是想要一个不那么尴尬的语法来直接观察嵌套对象，你可以简单地观察一个computed:

var vm = new Vue({
  el: '#app',
  computed: {
    foo() {
      return this.item.foo;
    }
  },
  watch: {
    foo() {
      console.log('Foo Changed!');
    }
  },
  data: {
    item: {
      foo: 'foo'
    }
  }
})

这是JSFiddle: http://jsfiddle.net/oa07r5fw/

这些答案对我来说都没用。实际上，如果你想观察嵌套的数据与组件被多次调用。所以他们被称为不同的道具来识别他们。 例如<MyComponent chart="chart1"/> <MyComponent chart="chart2"/> 我的解决方法是创建一个额外的vuex状态变量，我手动更新它以指向上次更新的属性。

这是一台Vuex。Ts实现示例:

export default new Vuex.Store({
    state: {
        hovEpacTduList: {},  // a json of arrays to be shared by different components, 
                             // for example  hovEpacTduList["chart1"]=[2,6,9]
        hovEpacTduListChangeForChart: "chart1"  // to watch for latest update, 
                                                // here to access "chart1" update 
   },
   mutations: {
        setHovEpacTduList: (state, payload) => {
            state.hovEpacTduListChangeForChart = payload.chart // we will watch hovEpacTduListChangeForChart
            state.hovEpacTduList[payload.chart] = payload.list // instead of hovEpacTduList, which vuex cannot watch
        },
}

在任何Component函数上更新存储:

    const payload = {chart:"chart1", list: [4,6,3]}
    this.$store.commit('setHovEpacTduList', payload);

现在对任何组件进行更新:

    computed: {
        hovEpacTduListChangeForChart() {
            return this.$store.state.hovEpacTduListChangeForChart;
        }
    },
    watch: {
        hovEpacTduListChangeForChart(chart) {
            if (chart === this.chart)  // the component was created with chart as a prop <MyComponent chart="chart1"/> 
                console.log("Update! for", chart, this.$store.state.hovEpacTduList[chart]);
        },
    },

跟踪列表中单个更改的项

如果你想监视列表中的所有项目，并知道列表中的哪个项目发生了变化，你可以在每个项目上分别设置自定义监视器，如下所示:

var vm = new Vue({
  data: {
    list: [
      {name: 'obj1 to watch'},
      {name: 'obj2 to watch'},
    ],
  },
  methods: {
    handleChange (newVal, oldVal) {
      // Handle changes here!
      // NOTE: For mutated objects, newVal and oldVal will be identical.
      console.log(newVal);
    },
  },
  created () {
    this.list.forEach((val) => {
      this.$watch(() => val, this.handleChange, {deep: true});
    });
  },
});

如果你的列表没有立即填充(就像在最初的问题中)，你可以将逻辑从created移到任何需要的地方，例如在.then()块中。

观察不断变化的列表

如果你的列表本身更新到有新的或删除的项目，我已经开发了一个有用的模式，“浅层”观察列表本身，并动态观察/取消观察项目随着列表的变化:

// NOTE: This example uses Lodash (_.differenceBy and _.pull) to compare lists
//       and remove list items. The same result could be achieved with lots of
//       list.indexOf(...) if you need to avoid external libraries.

var vm = new Vue({
  data: {
    list: [
      {name: 'obj1 to watch'},
      {name: 'obj2 to watch'},
    ],
    watchTracker: [],
  },
  methods: {
    handleChange (newVal, oldVal) {
      // Handle changes here!
      console.log(newVal);
    },
    updateWatchers () {
      // Helper function for comparing list items to the "watchTracker".
      const getItem = (val) => val.item || val;

      // Items that aren't already watched: watch and add to watched list.
      _.differenceBy(this.list, this.watchTracker, getItem).forEach((item) => {
        const unwatch = this.$watch(() => item, this.handleChange, {deep: true});
        this.watchTracker.push({ item: item, unwatch: unwatch });
        // Uncomment below if adding a new item to the list should count as a "change".
        // this.handleChange(item);
      });

      // Items that no longer exist: unwatch and remove from the watched list.
      _.differenceBy(this.watchTracker, this.list, getItem).forEach((watchObj) => {
        watchObj.unwatch();
        _.pull(this.watchTracker, watchObj);
        // Optionally add any further cleanup in here for when items are removed.
      });
    },
  },
  watch: {
    list () {
      return this.updateWatchers();
    },
  },
  created () {
    return this.updateWatchers();
  },
});

另一种更好的方法是:

 watch:{
     'item.someOtherProp': function (newVal, oldVal){
         //to work with changes in someOtherProp
     },
     'item.prop': function(newVal, oldVal){
         //to work with changes in prop
     }
 }

(我从评论里的@peerbolte那里学到了这个方法)