Flutter navigation, reopen page instead of pushing it again

问题

I'm new to flutter and I'm working on an App that have multiple screens.

I would like to know to stop flutter from creating multiple screens of the same route, for example I have Page 1 and Page 2, if I click on the button to navigate to Page 2 and clicked again on the same button the application will push a new screen of Page 2 and i will have it twice and if I click on the return button it will send me back to the first created Page 2

is there a way to create every page only once and then reopen it if it's already pushed to the stack ?

I'm using Navigator.push for all my navigation

回答1:

Using a simple logic here

1. If the new page is the same as the current page then use Navigator.push(context,route).

2. If the new page is the different then use Navigator.pushReplacement(context,route).

---

In case if you are using named routes then for

1. same page as current, use Navigator.pushNamed(context,name).
2. different page, use Navigator.pushReplacementNamed(context,name).

---

Complete code sample

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

class SO extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: PageOne(),
    );
  }
}

class PageOne extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Page 1'),
      ),
      backgroundColor: Colors.amber,
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            RaisedButton(
              onPressed: () {
                print('creating replacement page 1');
                Navigator.pushReplacement(context, MaterialPageRoute(builder: (BuildContext context) {
                  return PageOne();
                }));
              },
              child: Text('Go to page 1'),
            ),
            RaisedButton(
              onPressed: () {
                print('creating new page 2');
                Navigator.push(context, MaterialPageRoute(builder: (BuildContext context) {
                  return PageTwo();
                }));
              },
              child: Text('Go to page 2'),
            ),
          ],
        ),
      ),
    );
  }
}

class PageTwo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Page 2'),
      ),
      backgroundColor: Colors.brown,
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            RaisedButton(
              onPressed: () {
                print('creating new page 1');
                Navigator.push(context, MaterialPageRoute(builder: (BuildContext context) => PageOne()));
              },
              child: Text('Go to page 1'),
            ),
            RaisedButton(
              onPressed: () {
                print('creating replacement page 2');
                Navigator.pushReplacement(context, MaterialPageRoute(builder: (BuildContext context) => PageTwo()));
              },
              child: Text('Go to page 2'),
            ),
          ],
        ),
      ),
    );
  }
}

回答2:

You should use Navigator.pushReplacement(). Here are the docs: https://api.flutter.dev/flutter/widgets/NavigatorState/pushReplacement.html

In summary, when you call pushReplacement, it pushes a new page but also disposes of the previous one. Now, when you press the back button, it should bring you back to page 1.

来源：https://stackoverflow.com/questions/59457306/flutter-navigation-reopen-page-instead-of-pushing-it-again