Why when I use the navigator to go to another page(widget) that covers just part of the screen, I can't see the first-page content (which is on top of the page)?

I tried code from this example (

CodePudding user response：

use this class instead of your class

    class SecondRoute extends StatelessWidget {
  const SecondRoute({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Second Route'),
      ),
      body: Container(
      padding:const EdgeInsets.only(top:128),
        child: Center(
          child: ElevatedButton(
            onPressed: () {
              Navigator.pop(context);
            },
            child: const Text('Go back!'),
          ),
        ),
      ),
    );
  }
}