【Ant Design已解决】a-date-picker已经选择值，但是不识别

<a-date-picker format='YYYY'
               :open='yearFlag'
               placeholder="请选择采购时间"
               style='width: 100%'
               @panelChange='(value) => {
                 data.buyTime =String(value.year());yearFlag = false; }'
               @openChange='(value) => {if(value){yearFlag = true}else{yearFlag = false}}'
               mode='year'
               v-model='data.buyTime'
               class='picker'
               :disabledDate="disabledDate"
/>
buyTime: {
  required: true,
  trigger: ['blur', 'change'],
  message: '请选择采购时间（年份）'
}
data() {
	return {
	data: {
	//加上这个
		buyTime: null
     },
}