private void TabItem_MouseUp_3(object sender, MouseButtonEventArgs e)
        {
            DeleteBuilding delBuilding        = new DeleteBuilding();
            DeleteBuilding AddTaskUserControl = new DeleteBuilding();

            DockPanel.SetDock(AddTaskUserControl, Dock.Top);
            SwitchContainer.Children.Clear();
            SwitchContainer.Children.Add(AddTaskUserControl);
        }
        private void Button_Click_3(object sender, RoutedEventArgs e)
        {
            DeleteBuilding delBuilding        = new DeleteBuilding();
            DeleteBuilding AddTaskUserControl = new DeleteBuilding();

            DockPanel.SetDock(AddTaskUserControl, Dock.Top);
            SwitchContainer.Children.Clear();
            SwitchContainer.Children.Add(AddTaskUserControl);
        }
        public void DeleteBuild()
        {
            clearTextBox();
            buildingError.Opacity = 0;
            Int32 id = Convert.ToInt32(BuildingIDField.Text);

            try
            {
                Building building = Read_BuildingID(id);
                Console.WriteLine("Gebäude: " + building.name);

                name.Text     = building.name;
                street.Text   = building.street;
                streetNr.Text = building.streetNr;
                postcode.Text = Convert.ToString(building.postcode);
                place.Text    = building.place;
                purpose.Text  = building.purpose;

                Delete(building);
                // TEST
                if (DeleteBuilding.Read_BuildingID(id) == null)
                {
                    deleteBuildingSuccessful.Opacity = 1;
                    Console.WriteLine("Löschen erfolgreich");
                }
                else
                {
                    deleteBuildingSuccessful.Opacity = 0;
                    Console.WriteLine("Löschen NICHT erfolgreich");
                }
            }
            catch (Exception ex)
            {
                deleteBuildingSuccessful.Opacity = 0;
                if (name.Text == "" && street.Text == "" && streetNr.Text == "" && postcode.Text == "")
                {
                    buildingError.Content = "Dieses Gebäude existiert nicht";
                    buildingError.Opacity = 1;
                }
                else
                {
                    buildingError.Content = "In diesem Gebäude wohnt noch jemand";
                    buildingError.Opacity = 1;
                }
            }
        }