Prevent Live Wallpaper orientation change when an

问题:

I'm having an orientation issue with a Live Wallpaper that I wrote. Basically the canvas will rotate depending on the application opened above it. I tested this and realized that the onSurfaceChanged() method is firing when I return to the home screen from a previously opened application who's orientation was changed.

I suppose a better question would be, why does my Live Wallpaper Surface Change when an application is opened and it's orientation changed? Is there a way to prevent my Live Wallpaper orientation from ever changing? Thanks, hope that makes sense?

回答1:

Android application restarts the activity when the orientation changes. You can either use

1. android:configChanges in your manifest. The activity is shut down and restarted by default, when a configuration change occurs at runtime, but declaring a configuration with this attribute will prevent the activity from being restarted. Instead, the activity remains running and its onConfigurationChanged() method is called.
2. use android:screenOrientatin = "portrait" or "landscape" it will force the app to run in the mode you specify. However it will not prevent the activity from being shut down and restarted.

回答2:

You can handle screen orientation from within the android.service.wallpaper.WallpaperService.Engine class with the following method:

public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height)

... just handle the event accordingly.

You CANNOT add android:configChanges nor android:screenOrientation to a WallpaperService! (Which you are using when creating a live wallpaper)

I would have added this as a comment to "Anirudha"'s answer, but I don't have enough reputation to do so.