如何更改ViewModel属性并将其保存到所有页面？

// 全局的ViewModel对象
const viewModel = new Vue({
  data: {
    property: '初始值'
  },
  methods: {
    updateProperty(newValue) {
      this.property = newValue;
    }
  }
});

// 页面A
new Vue({
  el: '#pageA',
  data: {
    localProperty: ''
  },
  mounted() {
    this.localProperty = viewModel.property;
  },
  methods: {
    updateViewModelProperty(newValue) {
      viewModel.updateProperty(newValue);
    }
  }
});

// 页面B
new Vue({
  el: '#pageB',
  data: {
    localProperty: ''
  },
  mounted() {
    this.localProperty = viewModel.property;
  },
  methods: {
    updateViewModelProperty(newValue) {
      viewModel.updateProperty(newValue);
    }
  }
});