Finish all service load complete check

Add the method below

when All Loading Complete then this method fire and busy indicator is inactive
        protected virtual void OnLoadingCompleted(EventArgs e)
        {
            --load complete
        }

        locker object for no call other
        private readonly object _locker = new object();
        private int _loadingCompletedCount;

        number of loading
        private const int TotalLoading = 13;

        Check how many loading are complete
        public void IsLoadingCompleted()
        {
            lock (_locker)
                ++_loadingCompletedCount;
            if (_loadingCompletedCount >= TotalLoading)
                OnLoadingCompleted(new EventArgs());
        }

and call IsLoadingCompleted() method into every load complte