private void DeleteTask(object o) { var taskList = o as System.Windows.Controls.ListBox; if (taskList.Items == null || taskList.Items.Count <= 0) { return; } var selectedTasks = taskList.SelectedItems.Cast <TaskModel>(); bool result = false; if (selectedTasks.Count() > 1) { result = MessageBox.Show("Do you want to delete the selected tasks ?", Enums.MessageTypes.Information.ToString(), MessageBoxButton.YesNo, MessageBoxImage.Question) == MessageBoxResult.Yes; } else if (selectedTasks.Count() == 1) { result = MessageBox.Show($"Do you want to delete the task '{selectedTasks.FirstOrDefault().Title}' ?", Enums.MessageTypes.Information.ToString(), MessageBoxButton.YesNo, MessageBoxImage.Question) == MessageBoxResult.Yes; } if (result) { taskBL.Delete(selectedTasks.Select(task => task.IdTask).ToList()); RefreshByFilter(); } }