public TradingViewModel(ViewModelContext viewModelContext, AccountViewModel accountViewModel, SymbolsViewModel symbolsViewModel, TradeViewModel tradeViewModel, OrdersViewModel ordersViewModel, IWpfExchangeService exchangeService, IAccountsService accountsService) : base(viewModelContext) { AccountViewModel = accountViewModel; SymbolsViewModel = symbolsViewModel; TradeViewModel = tradeViewModel; OrdersViewModel = ordersViewModel; Symbols = new ObservableCollection <SymbolViewModel>(); this.exchangeService = exchangeService; this.accountsService = accountsService; ObserveSymbols(); ObserveAccount(); ObserveTrade(); ObserveOrders(); CloseCommand = new ViewModelCommand(Close); }