Cannot resolve symbol Theme, ThemeOverlay

2019-01-24 01:37发布

问题:

I updated my android studio to latest version - 3.0.1. Since then it complains 'Cannot resolve symbol' for Theme and ThemeOverlay in the following lines of code. App runs fine but they are marked in RED in the file.

styles.xml

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"></style>
 <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

build.gradle is updated with the latest version

 dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
    }

回答1:

1)Close the project from the File menu.

2)Open the project again as existing Android Studio project.

This fix my problem.



回答2:

  1. In the app/build.gradle remove the line responsible for the appcompat package (something like implementation 'com.android.support:appcompat-v7:27.1.1')
  2. Perform the Gradle sync. It will break and show a lot of errors
  3. Bring the original line back
  4. Perform the Gradle sync once again

This will magically solve the problem that for no reason appeared in the 3.0.1



回答3:

Found Easiest Way

  • Close project (File> Close Project)
  • Import / Re-Open project again (NOT from Recent)

The error should be gone.

If(that_did_not_work)

  • Open build.gradle, remove appcompact-v7 dependency and sync.
  • Again add that dependency and sync.

Error Gone!