<x-picker-date id="picker-date" 
default-value="{{newTime}}" 
wx:if="{{showPicker}}" 
bind:myevent="toggleToast">
</x-picker-date>

showPickerDate(e) {
  this.setData({ showPicker: true })
  // 调用子组件中methods的onshow方法
  this.selectComponent('#picker-date').onshow()
},
// 获取子组件信息
toggleToast(e){
    console.log(e.detail)
}

properties: {
// 父组件传值
    defaultValue: {
      type: String,
      value: 'default value',
    }
  },
methods: {
    onshow() {
        console.log(this.data.defaultValue)
    },
    // 传递给父组件
    cancelBut: function (e) {
      var that = this;
      var myEventDetail = { pickerShow: false, type: 'cancel' } // detail对象，提供给事件监听函数
      this.triggerEvent('myevent', myEventDetail) //myevent自定义名称事件，父组件中使用
    },
}