Error: Method 'addPostFrameCallback' cannot be called on 'SchedulerBinding?'

Question

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( ^^^^^^^^^^^^^^^^^^^^

Answer 1

This error happens because the package get 4.6.2 or 4.6.3 is for new flutter sdk version 3.0. So you got this error. you have to use get 4.6.1 for fluter SDK version 2.xx

I had the same problem.. on "dart.get" package. Then I did this..

First go to pubspec.yaml file then edit the get version not more than (get: ^4.6.1).. if you are using fluter sdk v2.xx.

if the version won't get lower then try this method

go to pubspec.lock file. edit the version not more than (4.6.1).. if you are using fluter sdk v2.xx.

you will find in pubspec.lock file

and last you have to do this

then "pub get" .. error will be gone.

Answer 2

This is because of recent flutter updates. All flutter SDKs >= V2.10.3 have this issue. There's no proper solution for this error yet.

Temporary Solution:

You can simply downgrade your flutter SDK to V2.10.2 or lower to get rid of this issue.

Note:

After downgrading, make sure you also change the dart version in pubspec.yaml of your flutter project according to the Flutter SDK.

Answer 3

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