How To Solve SchedulerBinding issue?

Question

/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_navigation/src/extension_navigation.dart:357:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
 - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/scheduler/binding.dart').
      SchedulerBinding.instance!.addPostFrameCallback((_) {
                       ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_navigation/src/extension_navigation.dart:468:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
 - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/scheduler/binding.dart').
      SchedulerBinding.instance!.addPostFrameCallback((_) {
                       ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_navigation/src/snackbar/snackbar.dart:452:22: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
 - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/scheduler/binding.dart').
    SchedulerBinding.instance!.addPostFrameCallback(
                     ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_state_manager/src/rx_flutter/rx_disposable.dart:20:22: Warning: Operand of null-aware operation '?.' has type 'SchedulerBinding' which excludes null.
 - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/scheduler/binding.dart').
    SchedulerBinding.instance?.addPostFrameCallback((_) => onReady());
                     ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_state_manager/src/rx_flutter/rx_notifier.dart:130:22: Warning: Operand of null-aware operation '?.' has type 'SchedulerBinding' which excludes null.
 - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/scheduler/binding.dart').
    SchedulerBinding.instance?.addPostFrameCallback((_) => onReady());
                     ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_state_manager/src/simple/get_controllers.dart:90:20: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
 - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/widgets/binding.dart').
    WidgetsBinding.instance!.addObserver(this);
                   ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_state_manager/src/simple/get_controllers.dart:96:20: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
 - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/widgets/binding.dart').
    WidgetsBinding.instance!.removeObserver(this);
                   ^
/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.1/lib/get_navigation/src/router_report.dart:53:22: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
 - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/C:/src/flutter/packages/flutter/lib/src/widgets/binding.dart').
      WidgetsBinding.instance!.addPostFrameCallback((_) {
                     ^

Answer 1

You can upgrade your flutter to version 3 and upgrade Getx package to 4.6.5

Answer 2

running

dart fix --apply

should fix that.

source: https://github.com/flutter/flutter/issues/99272