问题
Whenever I clean my project is says: PSI and index do not match What should I do?
回答1:
Important note: This will wipe the shelf, local history, and potentially other cached data.
File menu > Invalidate caches and restart. The PSI cache is one of the caches that are affected by this command, so this should fix it up.
回答2:
Whenever I navigated to a class, I'd get this PSI error. Clicking the details in Android Studio, it included the following:
viewProvider=SingleRootFileViewProvider{myVirtualFile=jar://<user-directory>/.gradle/caches/modules-2/files-2.1/com.squareup.haha/haha/2.0.3/e0672395ac43377f2510b14839342a24fdf35c18/haha-2.0.3-sources.jar!/com/squareup/haha/guava/io/GwtWorkarounds.java, content=VirtualFileContent{size=5678}}
Based on this info, I tried deleting <user-directory>/.gradle/caches/modules-2 and restarting Android Studio and it seemed to fix the PSI error, and it didn't seem to delete local history (though I don't know if anything else important was deleted).
回答3:
Invalidating caches didn't work for me. Only a complete re-install of AS and all relevant SDK, Gradle etc... did the trick. I started by uninstalling AS. Then I manually deleted the SDK folder. I also deleted the .gradle and .android folders in my C:/Users/[my.user]/ folder.
回答4:
Android Studio (windows) File -> Invalidate Caches/Restart...
then click on (Invalidate and Restart) button
回答5:
I have also faced this problem. I have solved this by going to
File menu > Invalidate caches and restart.
来源：https://stackoverflow.com/questions/28794723/psi-and-index-do-not-match-psi-and-index-do-not-match-on-android-studio