how can I fix this error in flutter with android studio

/C:/src/flutterSDK/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.6.3/lib/get_navigation/src/snackbar/snackbar.dart:452:31: Error: Method 'addPostFrameCallback' cannot be called on 'SchedulerBinding?' because it is potentially null.

• 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/C:/src/flutterSDK/flutter/packages/flutter/lib/src/scheduler/binding.dart'). Try calling using ?. instead. SchedulerBinding.instance.addPostFrameCallback( ^^^^^^^^^^^^^^^^^^^^

CodePudding user response：

Error:

The error is saying the instance of SchedulerBinding(i.e SchedulerBinding.instance) can be null and so you should add a null check (?) to ensure that the addPostFrameCallback method is only called on a non-null instance.

Solution:

Update:

SchedulerBinding.instance.addPostFrameCallback

to:

SchedulerBinding.instance?.addPostFrameCallback // With '?' after instance

Checkout Understanding null safety | Dart for more on Dart's null safety.

CodePudding user response：

This error is due to some changes happened in null-safety properties in Flutter 3.0.0. In your case you can try to import: get: 4.6.1 instead of get: ^4.6.3. Source: https://github.com/jonataslaw/getx/issues/2356