android - How to get the list of running applications?

Question

I am working on an app which needs the information of the apps running at the system up to now. Is there an API/method to retrieve that kind of information?

Answer 1

You cannot detect an App launch in Android, but you can get the list of currently open apps and check if the app you're looking for is open or not using the following code:

ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningAppProcessInfo> runningAppProcessInfo = am.getRunningAppProcesses();

for (int i = 0; i < runningAppProcessInfo.size(); i++) {
  if(runningAppProcessInfo.get(i).processName.equals("com.the.app.you.are.looking.for")) {
    // Do your stuff here.
  }
}

You can also check if the app is running in the foreground using this method

public static boolean isForeground(Context ctx, String myPackage){
    ActivityManager manager = (ActivityManager) ctx.getSystemService(ACTIVITY_SERVICE);
    List< ActivityManager.RunningTaskInfo > runningTaskInfo = manager.getRunningTasks(1); 

    ComponentName componentInfo = runningTaskInfo.get(0).topActivity;
    if(componentInfo.getPackageName().equals(myPackage)) {
        return true;
    }       
    return false;
}