「VirtualDisplay 実装例」を API 29 の Emulator で実行すると下記ランタイムエラー。
2020-12-21 01:28:56.035 3538-3538/asia.remix.virtualdisplay E/AndroidRuntime: FATAL EXCEPTION: main Process: asia.remix.virtualdisplay, PID: 3538 java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=450066721, result=-1, data=Intent { (has extras) }} to activity {asia.remix.virtualdisplay/asia.remix.virtualdisplay.MainActivity}: java.lang.SecurityException: Media projections require a foreground service of type ServiceInfo.FOREGROUND_SERVICE_TYPE_MEDIA_PROJECTION at android.app.ActivityThread.deliverResults(ActivityThread.java:4845) at android.app.ActivityThread.handleSendResult(ActivityThread.java:4886) at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:51) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016) at android.os.Handler.dispatchMessage(Handler.java:107) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7356) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) Caused by: java.lang.SecurityException: Media projections require a foreground service of type ServiceInfo.FOREGROUND_SERVICE_TYPE_MEDIA_PROJECTION at android.os.Parcel.createException(Parcel.java:2071) at android.os.Parcel.readException(Parcel.java:2039) at android.os.Parcel.readException(Parcel.java:1987) at android.media.projection.IMediaProjection$Stub$Proxy.start(IMediaProjection.java:231) at android.media.projection.MediaProjection.API 29 から、getMediaProjection()の前に、サービスではないが startForeground() が必要...▼(MediaProjection.java:58) at android.media.projection.MediaProjectionManager.getMediaProjection(MediaProjectionManager.java:104) at asia.remix.virtualdisplay.MainActivity$1.onActivityResult(MainActivity.java:62) at asia.remix.virtualdisplay.MainActivity$1.onActivityResult(MainActivity.java:57) at androidx.activity.result.ActivityResultRegistry.doDispatch(ActivityResultRegistry.java:377) at androidx.activity.result.ActivityResultRegistry.dispatchResult(ActivityResultRegistry.java:336) at androidx.activity.ComponentActivity.onActivityResult(ComponentActivity.java:624) at androidx.fragment.app.FragmentActivity.onActivityResult(FragmentActivity.java:164) at android.app.Activity.dispatchActivityResult(Activity.java:8110) at android.app.ActivityThread.deliverResults(ActivityThread.java:4838) at android.app.ActivityThread.handleSendResult(ActivityThread.java:4886) at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:51) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016) at android.os.Handler.dispatchMessage(Handler.java:107) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7356) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) Caused by: android.os.RemoteException: Remote stack trace: at com.android.server.media.projection.MediaProjectionManagerService$MediaProjection.start(MediaProjectionManagerService.java:476) at android.media.projection.IMediaProjection$Stub.onTransact(IMediaProjection.java:135) at android.os.Binder.execTransactInternal(Binder.java:1021) at android.os.Binder.execTransact(Binder.java:994)