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| public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
List1.Items.Add("Финансы");
List1.Items.Add("Бухгалтерия");
List2.Items.Add("Экономика");
List2.Items.Add("Бизнес");
List2.Items.Add("Интернет");
List2.SelectionMode = SelectionMode.Multiple;
PrepareListBoxForDragDrop(List1);
PrepareListBoxForDragDrop(List2);
}
private void PrepareListBoxForDragDrop(ListBox listbox)
{
List1.AllowDrop = true;
listbox.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(ListboxPreviewMouseLeftButtonDown);
listbox.PreviewMouseMove += new MouseEventHandler(ListboxPreviewMouseMove);
listbox.PreviewMouseLeftButtonUp += new MouseButtonEventHandler(ListboxPreviewMouseLeftButtonUp);
listbox.Drop += new DragEventHandler(ListboxDrop);
}
private static DependencyProperty DraggingElementProperty = DependencyProperty.RegisterAttached(
"DraggingElement", typeof(string), typeof(MainWindow), new FrameworkPropertyMetadata(null));
private static DependencyProperty IsDownProperty = DependencyProperty.RegisterAttached(
"IsDown", typeof(bool), typeof(MainWindow), new FrameworkPropertyMetadata(false));
private static DependencyProperty StartPointProperty = DependencyProperty.RegisterAttached(
"StartPoint", typeof(Point), typeof(MainWindow), new FrameworkPropertyMetadata(default(Point)));
private void ListboxPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
ListBox listbox = (ListBox)sender;
string s = GetBoundItemFromPoint(listbox, e.GetPosition(listbox));
if (s != null)
{
listbox.SetValue(IsDownProperty, true);
listbox.SetValue(DraggingElementProperty, s);
listbox.SetValue(StartPointProperty, e.GetPosition(listbox));
}
}
private string GetBoundItemFromPoint(ListBox box, Point point)
{
UIElement element = box.InputHitTest(point) as UIElement;
while (element != null)
{
if (element == box)
{
return null;
}
object item = box.ItemContainerGenerator.ItemFromContainer(element);
bool itemFound = !object.ReferenceEquals(item, DependencyProperty.UnsetValue);
if (itemFound)
{
return (string)item;
}
else
{
element = VisualTreeHelper.GetParent(element) as UIElement;
}
}
return null;
}
private void ListboxPreviewMouseMove(object sender, MouseEventArgs e)
{
ListBox listbox = (ListBox)sender;
bool isDown = (bool)listbox.GetValue(IsDownProperty);
if (!isDown)
{
return;
}
Point startPoint = (Point)listbox.GetValue(StartPointProperty);
if (Math.Abs(e.GetPosition(listbox).X - startPoint.X) > SystemParameters.MinimumHorizontalDragDistance ||
Math.Abs(e.GetPosition(listbox).Y - startPoint.Y) > SystemParameters.MinimumVerticalDragDistance)
{
DragStarted(listbox);
}
}
private void DragStarted(ListBox List2)
{
List2.ClearValue(IsDownProperty);
System.Collections.ArrayList selected = new System.Collections.ArrayList(List2.SelectedItems);
foreach (Object selectedItem in selected)
{
string draggingElement = selectedItem.ToString();
DataObject d = new DataObject(DataFormats.UnicodeText, draggingElement);
DragDropEffects effects = DragDrop.DoDragDrop(List2, d, DragDropEffects.Copy | DragDropEffects.Move);
if ((effects & DragDropEffects.Move) != 0)
{
List1.ClearValue(IsDownProperty);
List2.Items.Remove(draggingElement);
}
}
}
private void ListboxDrop(object sender, DragEventArgs e)
{
ListBox List2 = (ListBox)sender;
if (e.Data.GetDataPresent(DataFormats.UnicodeText, true))
{
List2.Items.Add((string)e.Data.GetData(DataFormats.UnicodeText, true));
e.Effects =
((e.KeyStates & DragDropKeyStates.ControlKey) != 0) ?
DragDropEffects.Copy : DragDropEffects.Move;
e.Handled = true;
}
}
private void ListboxPreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
ListBox listbox = (ListBox)sender;
listbox.ClearValue(IsDownProperty);
listbox.ClearValue(DraggingElementProperty);
listbox.ClearValue(StartPointProperty);
}
private void button1_Click(object sender, RoutedEventArgs e)
{
System.Collections.ArrayList selected = new System.Collections.ArrayList(List2.SelectedItems);
foreach (Object selectedItem in selected)
{
List2.Items.Remove(selectedItem);
List1.Items.Add(selectedItem);
}
}
} |
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