مطابق آموزش بادی سنتر قرار دادم ولی وسط چین نشد

appBar: AppBar(
  // TRY THIS: Try changing the color here to a specific color (to
  // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
  // change color while the other colors stay the same.
  backgroundColor: Theme.of(context).colorScheme.inversePrimary,
  // Here we take the value from the MyHomePage object that was created by
  // the App.build method, and use it to set our appbar title.
  title: Text(widget.title),
),
body: Center(
  // Center is a layout widget. It takes a single child and positions it
  // in the middle of the parent.
  child: Center(
    child: Column(
      // Column is also a layout widget. It takes a list of children and
      // arranges them vertically. By default, it sizes itself to fit its
      // children horizontally, and tries to be as tall as its parent.
      //
      // Column has various properties to control how it sizes itself and
      // how it positions its children. Here we use mainAxisAlignment to
      // center the children vertically; the main axis here is the vertical
      // axis because Columns are vertical (the cross axis would be
      // horizontal).
      //
      // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
      // action in the IDE, or press "p" in the console), to see the
      // wireframe for each widget.
      mainAxisAlignment: MainAxisAlignment.center,
      crossAxisAlignment: CrossAxisAlignment.center,
      children: <Widget>[
        const Text(
          'You have pushed the button this many times:',
        ),