changeMonth = (event, selectedNumber) => {
event.preventDefault()
this.setState(
{
isOpen: false,
// selectedMonth: selectedNumber
})
this.props.onChange(this.state.selectedYear, selectedNumber)
}

// 老师，child component 必须用onChange ，然后让parent 感知是吗？如果不用onChange,Parent 感受不到.

对应documentation写的：We can use the onChange event on the inputs to be notified of it. The callbacks passed by FilterableProductTable will call setState(), and the app will be updated.