I have a List of String stored in a variable like this:

var question = [
  'whats your favorite name',
  'whats your favorite color',
  'whats your favorite shape',
];

And have function that increase a variable each time I call it

void _Press(){
  setState((){
    _PressedNo = _PressedNo   1;
  });

  print(_PressedNo );
} 

And in my scaffold iam checking if the _PressedNo is smaller that List so it rebuild the scaffold with the new question each time i press the button till the questions finished like this :

return MaterialApp(
  home: Scaffold(
  body:_PressedNo < question.length ? Container( 
    child: RaisedButton(
      child: Text('yes'),
      onPressed:() {
        _Press();
      },
    ), 
  ) : // here i want to go to another page

And after the else : i want to go to another Flutter page, but I can only add widgets here so any solution how to do that..

CodePudding user response：

You'll have to take a bit of a different approach. The build method should only provide things that appear on the screen and not directly trigger a specific action or state change, such as navigating to another page.

You can handle this in the _Press() method:

void _Press() {
  if(_PressedNo < questions.length) {
    setState(() {
      _PressedNo = _PressedNo   1;
    });
  } else {
    Navigator.of(context).push(...); // navigate to another page

    // optionally set the _PressedNo back to 0
    setState(() { 
      _PressedNo = 0;
    });
  }
}

Your build method should not change, since on this page it should always show the same button.

return MaterialApp(
  home: Scaffold(
  body: Container( 
    child: RaisedButton(
      child: Text('yes'),
      onPressed:() {
        _Press();
      },
    ), 
  ),
);

Some other pointers:

• use lowerCase for functions and variables: _press() and _pressedNo.
• You can directly pass in the function to onPressed like onPressed: _press, (note that there are no parentheses since the function is not called but just passed along)