Widget _onTapOutside(BuildContext context) {
    var controller = TextEditingController();
    return Container(
      color: Colors.yellow,
      alignment: Alignment.center,
      height: 90,
      child: SizedBox(
        height: 60,
        child: TDInput(
          size: TDInputSize.small,
          leftLabel: '标签文字',
          controller: controller,
          backgroundColor: Colors.white,
          hintText: '请输入文字',
          onChanged: (text) {
            setState(() {});
          },
          onClearTap: () {
            controller.clear();
            setState(() {});
          },
          onTapOutside: (event) {
            TDToast.showText('点击输入框外部区域', context: context);
            print('on tap outside ${event}');
          },
        ),
      ),
    );
  }