avatar-display

main.dart

import 'package:flutter/material.dart';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

var userProfilePictureValue = null;
// "https://i.ya-webdesign.com/images/cat-icon-png-12.png";

var alternateImage = "https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcS_KHSomPJYHhzvhZGL8qO7WXZm053aU6MgS3i-DywZgW24DecF";

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: Text("HEllo"),
          backgroundColor: Colors.green,
          actions: <Widget>[
            CircleAvatar(
              radius: 30,
              backgroundImage: userProfilePictureValue != null
                  ? NetworkImage(
                      userProfilePictureValue,
                    )
                  : NetworkImage(
                      alternateImage,
                    ),
//               child: Text('cat')
            )
          ],
        ),
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Text('Hello, World!', style: Theme.of(context).textTheme.headline4);
  }
}