private void DeleteButton_Click(object sender, RoutedEventArgs e)
{
DateTime date = (DateTime)dateSelectPicker.SelectedDate;
if (cashbox.DeletePerformance(performanceComboBox.Text, date))
{
msgDelete.Text = "Спектакль \"" + performanceComboBox.Text + "\" успешно удалён.";
}
else
{
msgDelete.Text = "Спектакль \"" + performanceComboBox.Text + "\" в указанную дату не найден.";
}
}