how to change flutter background image code example

Example 1: flutter background image

Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Welcome to Flutter',
      home: Container(
        decoration: BoxDecoration(
            image: DecorationImage(
                image: AssetImage("images/logo.png"), fit: BoxFit.cover)),
        child: Scaffold(
          backgroundColor: Colors.transparent,
          appBar: AppBar(
            elevation: 0,
            backgroundColor: Colors.transparent,
            title: Text('My App'),
            centerTitle: true,
            leading: IconButton(
                icon: Icon(
                  Icons.list,
                  color: Colors.white,
                ),
                onPressed: () {}),
          ),
        ),
      ),
    );
  }

Example 2: add bg image to scaffold flutter

@override
Widget build(BuildContext context) {
  return new Scaffold(
    body: new Stack(
      children: [
        new Container(
          decoration: new BoxDecoration(
            image: new DecorationImage(image: new AssetImage("images/background.jpg"), fit: BoxFit.cover,),
          ),
        ),
        new Center(
          child: new Text("Hello background"),
        )
      ],
    )
  );
}