public void OpenSetting() { SettingDialog dialog = new SettingDialog(); SettingDialogViewModel viewmodel = new SettingDialogViewModel(this); dialog.DataContext = viewmodel; dialog.Owner = this.Window; dialog.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterOwner; dialog.ShowDialog(); this.TweetCommand.RaiseCanExecuteChanged(); this.WhisperCommand.RaiseCanExecuteChanged(); }