flutter)How can I make the button position automatically adjust according to the screen size?-CodePudding

I'm making a learning app with flutter.

In our app, you have to put a button over the picture.

So, using positioned on the picture, I made it like the picture below.

      @override
  Widget build(BuildContext context){
    return Scaffold(
      backgroundColor: Colors.white,
      body: Stack(
        fit: StackFit.expand,
        children: <Widget>[
          Image(
              image: AssetImage("assets/oral_structure.png"),
              fit: BoxFit.fitWidth
          ),
          Positioned(
              top:385, left:17,
              child: FlatButton(
                child: Text('ㅂ', style: TextStyle(fontSize: 30,fontWeight: FontWeight.bold)),
                shape: CircleBorder(),
                onPressed: (){
                  Navigator.push(context, MaterialPageRoute(builder: (context) => B()),);
                },
              )
          ),//ㅂ

However, the problem with this is that the position of the buttons changes when using a phone with a large screen.

What can be done to prevent this?

CodePudding user response：

The button seems always in the same place. It should be independent of screen size.

I suspect your problem is rather with the fontSize of the text.

Try to remove the fontSize:, it should fix your problem

EDIT 1:

the problem is with fit: StackFit.expand, that forces the button to expand. You can keep it but wrap your button inside a SizedBox

const SizedBox(
  width: 200.0,
  height: 100.0,
  child: FlatButton(// your code here...),
)

CodePudding user response：

Try to get the width and height of screen, and calculate base on that with a radio.