public MainWindowViewModel() { _dialogService = DialogServiceFactory.GetDialogServiceInstance(); _fbTokenService = FacebookServiceFactory.GetFacebookTokenServiceInstance(); _settingsRepos = SettingsCreatorFactory.GetSetingsInstance(); GetTokenCommand = new DelegateCommand(async _ => { //Reset result ErrorMsg = null; FBToken = null; //End of - Reset result //Open loading indicator IsGettingData = true; Debug.WriteLine($"Email: {UserEmail} - Password: {UserPassword}"); string lastEmail = _settingsRepos.LastLoggedInEmail; if (UserEmail != lastEmail) { //Lưu lại email đã dùng để lấy token mới _settingsRepos.LastLoggedInEmail = UserEmail; } //Request new Facebook token var getTokenResult = await _fbTokenService.GetTokenInfoAsyncByLocMai(UserEmail, UserPassword); if (!getTokenResult.Success) { ErrorMsg = getTokenResult.Message; Debug.WriteLine(ErrorMsg); } else { FBToken = getTokenResult.UserTokenInfo.AccessToken; Debug.WriteLine($"Token: {FBToken}"); } //Remove loading indicator IsGettingData = false; }, _ => !string.IsNullOrEmpty(UserEmail) && !string.IsNullOrEmpty(UserPassword) && !IsGettingData); SaveTokenCommand = new DelegateCommand(_ => { //Cách lưu file text: https://stackoverflow.com/questions/45276878/creating-a-txt-file-and-write-to-it string filePath = _dialogService.ShowSaveFileDialog(); if (filePath == null) { return; } using (var tw = new StreamWriter(filePath, false)) { try { tw.Write(FBToken); //Thực hiện ghi file Debug.WriteLine($"Token was written to file: {filePath}"); } catch (Exception ex) { Debug.WriteLine(ex); } } }); }