检测 Android 应用何时进入后台

Question

在我的应用程序中，我需要检测我的应用程序是进入后台还是切换到同一应用程序的另一个活动......我知道我必须使用 onPause 方法......但我如何区分这两种情况？

Answer 1

private static boolean isApplicationGoingToBackground(final Context context) {

        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        List<RunningTaskInfo> tasks = am.getRunningTasks(1);
        if (!tasks.isEmpty()) {
            ComponentName topActivity = tasks.get(0).topActivity;
            if (!topActivity.getPackageName().equals(context.getPackageName())) {
                return true;
            }
        }

        return false;
    }

UPDATE: getRunningTasks has been declared to not be guaranteed to be accurate.

Call in onStop. onStop gets called after onStart of whatever takes over the screen - if its an activity in the same apk package then you're not going into the background. This does require the GET_TASKS permission.

Or bind to a service onStart & unbind onStop - the service will then be onDestroyed when all your activities are stopped (or track binds vs unbinds if you don't want to rely on onDestroyed getting called - because it might not..).

Answer 2

There is no direct approach to get the app status while background or foreground, but even i have faced this issue, and found the solution with onWindowFocusChanged and onStop. For more details: http://vardhan-justlikethat.blogspot.in/2013/05/android-solution-to-detect-when-android.html