Dart Null Safety

Follow these links bellow

• Migrating to null safety (dart.dev)
• Null safety in Flutter (flutter.dev)
  
• Sound null safety (dart.dev)
  
• Understanding null safety (dart.dev)
  
• Unsound null safety (dart.dev)
  

So,  if you want to run the project without any further of error sound from null safety check. Just type and enter this command bellow:

flutter run --debug -d chrome --web-renderer html --no-sound-null-safety --hot (enter)

The last one. Run this command bellow to build your Flutter to be a web app.

flutter build web --dart-define=FLUTTER_WEB_USE_SKIA=true --web-renderer html --release --no-sound-null-safety (enter)

or,

flutter build web --dart-define=FLUTTER_WEB_USE_SKIA=true --web-renderer canvaskit --release --no-sound-null-safety (enter)

Explanation of the different between build web renderer into html or canvaskit, you can watch here. Watch complete events of Flutter Engage here. Or you can read here.

for preview build web on local-pc, type:

dhttpd --host=127.0.0.1 --port=2021 --path=build/web/ (enter)

Open on your web browser (chrome) as New Incognito Browser,

then type in URL bar: http://127.0.0.1:2021 (enter)