Flutter开发问题记录-持续更新中

1、flutter的GestureDetector 点击没反应

GestureDetector需要添加behavior: HitTestBehavior.opaque

GestureDetector(
  behavior: HitTestBehavior.opaque,
  child: GestureDetector(
            behavior: HitTestBehavior.opaque,
            onTap: (){
              print("hehe");
            },

2、Flutter中ListView使用顶部出现空白间隔 44

没配合AppBar使用顶部出现空白，ListView头部有一段空白区域，是因为当ListView没有和AppBar一起使用时，头部会有一个padding，为了去掉padding，可以使用MediaQuery.removePadding

Widget _listView(BuildContext context){
    return MediaQuery.removePadding(
      removeTop: true,
      context: context,
      child: ListView.builder(
        itemCount: 10,
        itemBuilder: (context,index){
          return _item(context,index);
        },

      ),
    );
  }

3、Column如何让两个控件都是左对齐

同时使用  mainAxisAlignment: MainAxisAlignment.start, crossAxisAlignment: CrossAxisAlignment.stretch

child: Column(
  mainAxisAlignment: MainAxisAlignment.start,
  crossAxisAlignment: CrossAxisAlignment.stretch,
  children: [
    Align(
      alignment: Alignment.centerLeft,
      child: GestureDetector(
          onTap: () {
            Navigator.pop(context);
          },
          child: Container(
              height: 45,
              child: Image.asset('assets/${StyleConfig.instance.assetsImageMiddlePath}theme_normal_back.png')
            ),
        ),
    ),
    Align(
      alignment: Alignment.centerLeft,
      child: Text(
        this.title,
        style: TextStyle(
          color: Colors.black87,
          fontWeight: FontWeight.bold,
          fontSize: 25,
        ),
      ),
    ),
  ],
),

4、Flutter Navigator operation requested with a context that does not include a Navigat

直接在 MaterialApp 中使用 Navigator 是会报 Navigator operation requested with a context that does not include a Navigat. ...

return MaterialApp(
      navigatorObservers: [routeObserver],
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: BlocProvider(
          builder: (context) {
            return SettingBloc(settingRepository: SettingRepository());
          },
          child: BottomButton(
              onPressed: () {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => LanguagePage(),
                ),
              );
            }
          ),
        ),
      ),
      builder: (BuildContext context, Widget child) {
        return MediaQuery(
            child: child,
            data: MediaQuery.of(context).copyWith(textScaleFactor: 1.0));
      },
    );

要使用 路由(Navigator)，根控件不能直接是 MaterialApp.解决方法：将 MaterialApp 内容再使用 StatelessWeight 或 StatefulWeight 包裹一层;

5、Widght传入带返回参数的方法-Dart语法

///点击item index
typedef void OnItemTapCompletion(int index);


@immutable
class CommonList extends StatelessWidget {
  List items;

  OnItemTapCompletion onTap;

  CommonList({this.items, this.onTap});
}

使用
  Widget _buildItem(BuildContext context, int index) {
    return Column(
      children: [
        GestureDetector(
          behavior: HitTestBehavior.opaque,
          onTap: () => this.onTap(index),
          child: Container(
            padding: const EdgeInsets.only(left: 15.0, right: 15.0),
            alignment: AlignmentDirectional.centerStart,
            height: 60,
            child: _buildItemContent(context, index),
          ),
        ),
        Divider(
          color: StyleConfig.instance.baseColorPrimarySeparator,
          height: 1,
          indent: 15,
        )
      ],
    );
  }

6、原生跳转到Flutter页面瞬间显示启动页面

    在FlutterBaseViewController设置setSplashScreenView为nil

    if ([viewController respondsToSelector:@selector(setSplashScreenView:)]) {

        [viewController performSelector:@selector(setSplashScreenView:) withObject:nil];

    }