ScaffoldMessenger class not found

[YWD]

where is ScaffoldMessenger!!!

[ayaankhan98]

@YWD Scaffold Messenger is introduced here, please fetch the latest changes from flutter/flutter master.
hope this clears your concern

[Alabhya268]

@YWD please upgrade flutter to master branch as ScaffoldMessanger is newly add

[ayaankhan98]

@Alabhya268 i do have upgraded version of master branch, i was just telling @YWD about it, as he had created a issue for this.

[Alabhya268]

@YWD i do have upgraded version of master branch, i was just telling @YWD about it, as he had created a issue for this.

@ayaankhan98 sorry it's my fault.i misunderstood the comment

[YWD]

I'm using the latest master channel!

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel master, 1.23.0-19.0.pre.92, on Mac OS X 10.15.4 19E287
darwin-x64, locale en-CN)
[!] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
! Some Android licenses not accepted. To resolve this, run: flutter doctor
--android-licenses
[✓] Xcode - develop for iOS and macOS (Xcode 12.0.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 4.0)
[✓] IntelliJ IDEA Ultimate Edition (version 2019.1)
[✓] VS Code (version 1.41.1)
[✓] Connected device (2 available)

! Doctor found issues in 1 category.

[YWD]

Oh, It's Android Studio's problem, I have two flutter environment on my computer, and I use stable channel for one project, master channel for gallery. but the 'flutter SDK path' set for gallery project didn't work. I check master channel's scaffold.dart and find there did have 'ScaffoldMessenger'.
Thanks @ayaankhan98 @Alabhya268

[r100-stack]

I solved this problem by changing the Flutter channel to master. (#350 (comment))

Hence, run the following in the command line

flutter channel master
flutter upgrade

[umershaekoor]

You might need to restart your IDE to remove the squiggly lines, after you've done the steps in in roshan's comment