【Flutter/Dart】アプリアイコンを設定する方法！flutter_launcher_icons

Flutter アプリ
├── android
├── ios
├── lib
│
├── assets
│     └── images
│            └── app_icon.png ← ココ
│
└── pubspec.yaml

$ flutter pub add flutter_launcher_icons

pubspec.yaml
// 〜〜〜〜〜〜
dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.8
  flutter_launcher_icons: ^0.14.3

dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_lints: ^5.0.0
// アイコン自動生成設定
flutter_icons:
  ios: true
  android: true
  image_path_ios: "assets/images/app_icon.png" // 画像パス
  image_path_android: "assets/images/app_icon.png" // 画像パス
  adaptive_icon_background: '#000000'
  adaptive_icon_foreground: "assets/images/app_icon.png" // 画像パス
  adaptive_icon_padding: true

flutter:
  uses-material-design: true

$ flutter pub run flutter_launcher_icons:main

Deprecated. Use `dart run` instead.
This command is deprecated and replaced with "flutter pub run flutter_launcher_icons"
  ════════════════════════════════════════════
    FLUTTER LAUNCHER ICONS (v0.14.3)                               
  ════════════════════════════════════════════
  

⚠ Warning: flutter_icons has been deprecated please use flutter_launcher_icons instead in your yaml files
• Creating default icons Android
• Overwriting the default Android launcher icon with a new icon
• Creating adaptive icons Android
• Updating colors.xml with color for adaptive icon background
• Creating mipmap xml file Android

WARNING: Icons with alpha channel are not allowed in the Apple App Store.
Set "remove_alpha_ios: true" to remove it.

• Overwriting default iOS launcher icon with new icon
No platform provided

✓ Successfully generated launcher icons