有没有办法在Android中获取所有当前处于活动状态的应用程序？

Question

I need to lock other apps when they are opened by the user in some time period, but I don't want to implement a service that will check after every second that which app is opened and lock accordingly. I want that, somehow, Android will broadcast with active app information.

Is it possible, and if yes, how?

Answer 1

Call ActivityManager.getRunningAppProcesses() , It will give you the list of running apps.If you want to see the details then iterate through the ActivityManager.RunningAppProcessInfo objects.

you can also check if your app is in Background or not by:

public static boolean isAppIsInBackground(Context context) {
    boolean isInBackground = true;
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {
        List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();
        for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {
            if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                for (String activeProcess : processInfo.pkgList) {
                    if (activeProcess.equals(context.getPackageName())) {
                        isInBackground = false;
                    }
                }
            }
        }
    } else {
        List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
        ComponentName componentInfo = taskInfo.get(0).topActivity;
        if (componentInfo.getPackageName().equals(context.getPackageName())) {
            isInBackground = false;
        }
    }

    return isInBackground;
}

Answer 2

I want that, somehow, Android will broadcast with active app information.

That does not exist.