scaffoldMessengerKey property Null safety
final
A key to use when building the ScaffoldMessenger.
If a scaffoldMessengerKey is specified, the ScaffoldMessenger can be directly manipulated without first obtaining it from a BuildContext via ScaffoldMessenger.of: from the scaffoldMessengerKey, use the GlobalKey.currentState getter.
Implementation
final GlobalKey<ScaffoldMessengerState>? scaffoldMessengerKey;