flutter

密码键盘

Posted by アライさん on 2020年10月20日

Flutter实现密码键盘。

难点：不要遮挡输入区域，像真正的键盘一样把输入区域顶上去。

使用keyboard_actions。 

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class MyPage extends StatefulWidget {
  static const routeName = '/myPage';

  @override
  _MyPageState createState() => _MyPageState();
}

class _MyPageState extends State<MyPage> {

  final _node = FocusNode();
  final ValueNotifier<String> _valueNotifier = ValueNotifier('');

  ///CellModel分组
  List<List<CellModel>> _cellGroupList = [];

  ///文字分组
  List<List<String>> _textGroupList = [];

  ///当前cell所在的group中的位置
  int _currGroupIndex = 0;

  ///当前cell所在list中的位置
  int _currListIndex = -1;

  @override
  void initState() {
    super.initState();
    _initAllCell();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: SimpleAppbar(
        title: '键盘',
      ),
      body: KeyboardActions(
        tapOutsideToDismiss: false,
        config: KeyboardActionsConfig(
          actions: [
            KeyboardActionsItem(
                focusNode: _node,
                displayActionBar: false,
                displayDoneButton: false,
                displayArrows: false,
                toolbarButtons: [],
                footerBuilder: (BuildContext context) {
                //自定义的键盘，需要implements PreferredSizeWidget，设置高度
                  return CustomKeyboard(
                    showNextGroup: true,
                    tap: (String action) {
                      _inputText(action);
                    },
                  );
                }),
          ],
        ),
        autoScroll: true,
        bottomAvoiderScrollPhysics: BouncingScrollPhysics(),
        child: Container(
          padding: EdgeInsets.symmetric(
            horizontal: ScreenUtil().setWidth(26),
          ),
          child: Column(
            mainAxisSize: MainAxisSize.max,
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisAlignment: MainAxisAlignment.start,
            children: [
              //方格组
              KeyboardInput<String>(
                focusNode: _node,
                notifier: _valueNotifier,
                builder: (context, text, hasFocus) {
                  int i = -1;
                  return Wrap(
                    runSpacing: ScreenUtil().setHeight(20),
                    spacing: ScreenUtil().setWidth(13),
                    runAlignment: WrapAlignment.start,
                    crossAxisAlignment: WrapCrossAlignment.start,
                    children: _cellGroupList.map((list) {
                      i++;
                      return _createGroup(i, list);
                    }).toList(),
                  );
                },
              ),
            ],
          ),
        ),
      ),
    );
  }

  ///创建group视图
  Widget _createGroup(int groupIndex, List<CellModel> cellModelList) {
    return ConstrainedBox(
      constraints: BoxConstraints(
        maxWidth: 100,
      ),
      child: GridView.builder(
        gridDelegate: SliverGridDelegateWithMaxCrossAxisExtent(
          //单个widget的水平最大宽度
          maxCrossAxisExtent: ScreenUtil().setWidth(127),
          //垂直单个子widget间距
          mainAxisSpacing: 0,
          //水平单个子widget间距
          crossAxisSpacing: 0,
          //item宽高比例
          childAspectRatio:
              ScreenUtil().setWidth(127) / ScreenUtil().setHeight(77),
        ),
        itemBuilder: (context, final index) {
          return SquareCell(
            statusIndex: cellModelList[index].statusIndex,
            text: _textGroupList[groupIndex][index] == ''
                ? 'P${index + 1}'
                : _textGroupList[groupIndex][index],
            hasFocus:
                (groupIndex == _currGroupIndex && index == _currListIndex),
            tap: () {
              setState(() {
                _currGroupIndex = groupIndex;
                _currListIndex = index;
                _node.requestFocus();
              });
            },
          );
        },
        padding: EdgeInsets.zero,
        itemCount: cellModelList.length,
        physics: NeverScrollableScrollPhysics(),
        cacheExtent: ScreenUtil().setHeight(77),
        shrinkWrap: true,
      ),
    );
  }

  ///监听键盘输入
  _inputText(String action) {

    _notifyValueChange();
    setState(() {});
  }


  ///初始化所有点
  _initAllCell({bool notify = false}) {
    _cellGroupList.clear();
    _textGroupList.clear();
    _cellGroupList.add([CellModel(), CellModel()]);
    _textGroupList.add(['', '']);
    _currGroupIndex = 0;
    _currListIndex = -1;
    if (notify) {
      setState(() {});
      _notifyValueChange();
    }

    ///延迟回收键盘
    Future.delayed(Duration(milliseconds: 300), () {
      _node.unfocus();
    });
  }
}




Tags
flutter