Antd<DataPicker/>allowClear点击清除后再次选择年份,能得到值,但是框上不显示值; 求解 求解....

Question

// 打开、关闭时间选择框
handleOpenChange = open => {

    if(open){      
        this.setState({isopen: true})    
    } else {      
        this.setState({isopen: false})    
    }  
};
//  设置值并且关闭时间选择框

handlePanelChange = (value) => {

this.setState({
    yearValue:value,
    isopen:false,
})

};
//获取光标 打开时间选择框
handleOnFocus =() =>{

  this.setState({
      isopen:true
  })

}
//清除值
handChange =() =>{

  this.setState({
      yearValue:null
  })

}

<Form.Item>
{getFieldDecorator('dataTime', {

    initialValue: this.state.yearValue
  })(<DatePicker 
    open={isopen}
    mode="year"
    format="YYYY" 
    placeholder='请选择年份'
    // allowClear={false}
    onFocus={this.handleOnFocus}
    onOpenChange={this.handleOpenChange}
    onPanelChange={this.handlePanelChange}
    onChange={this.handChange}
 />)} 

</Form.Item>