flutter 底部弹出菜单的实现

 FlatButton(
                  onPressed: () {
                    // print('提交数据');
                    _showCupertinoActionSheet();
                  },）




_showCupertinoActionSheet() async{
    var result = await showCupertinoModalPopup(
        context: context,
        builder: (context) {
          return CupertinoActionSheet(
            title: Text('提示'),
            message: Text('是否要删除当前项？'),
            actions: <Widget>[
              CupertinoActionSheetAction(
                child: Text('删除'),
                onPressed: () {
                  Navigator.of(context).pop('delete');
                },
                isDefaultAction: true,
              ),
              CupertinoActionSheetAction(
                child: Text('暂时不删'),
                onPressed: () {
                  Navigator.of(context).pop('not delete');
                },
                isDestructiveAction: true,
              ),
            ],
            cancelButton: CupertinoActionSheetAction(
              child: Text('取消'),
              onPressed: () {
                Navigator.of(context).pop('cancel');
              },
            ),
          );
        });
    setState(() {
      selectedVal = result;
    });