MaterialApp({ title,theme, home: Scaffold({ appBar, body: Center(child:Image.asset('assets/Krunal.jpg',),), }), })

 Image.asset():  direkt proje klasörüne eklenen resimleri uygualamaya dahil etme için pratik bir constructordür. 
                            yaml dosyasına resmin dosya dizin adresi eklenmelidir: assets:  - assets/Krunal.jpg

 
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Images',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Image Example'),
    );
  }
}
class MyHomePage extends StatelessWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(title),
      ),
      body: Center(
        child: ListView(
          children: <Widget>[
            Image.network(
              'https://picsum.photos/300?random',
              headers: {
                'Authentication': 'Basic xxxxx',
              },
            ),
            Image.asset('assets/images/sample.png'),
          ],
        ),
      ),
    );
  }
}

 
<b>dosya adı: pubspec.yaml
</b>
name: flutter_image_example
description: Flutter Image example
# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# Read more about versioning at semver.org.
version: 1.0.0+1
environment:
  sdk: ">=2.0.0-dev.68.0 <3.0.0"
dependencies:
  flutter:
    sdk: flutter
  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2
dev_dependencies:
  flutter_test:
    sdk: flutter
# For information on the generic Dart part of this file, see the
# following page: https://www.dartlang.org/tools/pub/pubspec
# The following section is specific to Flutter.
flutter:
  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true
  # To add assets to your application, add an assets section, like this:
  assets:
    - assets/images/sample.png
  #  - images/a_dot_ham.jpeg
  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.io/assets-and-images/#resolution-aware.
  # For details regarding adding assets from package dependencies, see
  # https://flutter.io/assets-and-images/#from-packages
  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.io/custom-fonts/#from-packages