flutter 过渡导出

在Android API上，我们可以使用

overridePendingTransition(int enterAnim, int exitAnim)

定义进入和退出转换。

如何在Flutter中做到这一点？

我已经实现了这段代码

class SlideLeftRoute extends PageRouteBuilder {
  final Widget enterWidget;
  SlideLeftRoute({this.enterWidget})
      : super(
      pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
        return enterWidget;
      },
      transitionsBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
        return SlideTransition(
          position: new Tween<Offset>(
            begin: const Offset(1.0, 0.0),
            end: Offset.zero,
          ).animate(animation),
          child: child
        );
      },

  );
}

但它仅定义输入转换。如何定义退出转场？

更新

想象一下，当我执行时，我有两个屏幕(Screen1和Screen2)

 Navigator.push(
        context, SlideLeftRoute(enterWidget: Screen2()));

我想将动画应用于Screen1和Screen2，而不仅是Screen2

example

最佳答案

我使用了不同的方式，但是diegodeveloper提供了类似的逻辑

截屏:



完整的代码:

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Page1(),
    );
  }
}

class Page1 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Page 1"),
        leading: Icon(Icons.menu),
      ),
      body: Container(
        color: Colors.grey,
        child: Center(
          child: RaisedButton(
            onPressed: () => Navigator.push(context, MyCustomPageRoute(previousPage: this, builder: (context) => Page2())),
            child: Text("2nd Page"),
          ),
        ),
      ),
    );
  }
}

class Page2 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("Page 2")),
      body: Container(
        color: Colors.blueGrey,
        child: Center(
          child: RaisedButton(
            onPressed: () => Navigator.pop(context),
            child: Text("Back"),
          ),
        ),
      ),
    );
  }
}

class MyCustomPageRoute extends MaterialPageRoute {
  final Widget previousPage;
  MyCustomPageRoute({this.previousPage, WidgetBuilder builder, RouteSettings settings}) : super(builder: builder, settings: settings);

  @override
  Widget buildTransitions(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget currentPage) {
    Animation<Offset> _slideAnimationPage1 = Tween<Offset>(begin: Offset(0.0, 0.0), end: Offset(-1.0, 0.0)).animate(animation);
    Animation<Offset> _slideAnimationPage2 = Tween<Offset>(begin: Offset(1.0, 0.0), end: Offset(0.0, 0.0)).animate(animation);
    return Stack(
      children: <Widget>[
        SlideTransition(position: _slideAnimationPage1, child: previousPage),
        SlideTransition(position: _slideAnimationPage2, child: currentPage),
      ],
    );
  }
}