问题
Just updated to 3.2.1 Android Studio
And i get the following errors when i try to run the app
Before the update everything was fine.
回答1:
Try to:
Build->Clean Project Then File->Invalidate Caches/Restart...->Invalidate and restart
If this doesn't work then Try Tools > Android > Sync Project with Gradle Files
Still not working then its time to get brutal.
File->Close Project.
Backup the project.
Get rid of the build/ directory (if you have one at the top and/or module levels) and the .gradle/ directory along with .idea/, build/, and .gradle/ of a project copy, then import it again.
And if this doesn't work.
Delete the same files again and also the .iml file from the project folder. Then, import the project using "Import Project(Gradle, Eclipse ATD..." from the welcome dialog that appeared when you chose Close Project earlier.
Don't forget to cross your finger while doing all of this.
来源：https://stackoverflow.com/questions/52911525/android-studio-update-3-2-1