how to do drag and drop an item from one listbox to another

Question

Is it possible to drag and drop an item from one Listbox to another? not remove but copy. from this Listbox . Actually, I have three listboxes, they are quite similar and I need to be able to drop an item(one from each Listbox ) to Listbox listHero

<ListBox x:Name="listhelmets" Height="214" Width="248" ItemsSource="{Binding ListHelmets}"
         IsSynchronizedWithCurrentItem="True" Canvas.Left="464" Canvas.Top="37" PreviewMouseDown="helmet_MouseDown1"
        PreviewMouseLeftButtonDown="helmet_PreviewMouseLeftButtonDown" DragLeave="helmet_DragLeave"
        PreviewMouseMove="helmet_PreviewMouseMove" SelectedValuePath="protection">
            <ListBox.ItemTemplate >
                <DataTemplate >
                    <StackPanel Orientation="Horizontal">
                        <Image Source="{Binding Path=Image}" Width="56" Height="61"/>
                        <TextBox Height="30" Width="30">
                          <Binding Path="protection" />
                           </TextBox>
                       </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

to this one

 <ListBox x:Name="listHero" Height="148" Width="158" 
            <ListBox.ItemTemplate >
                <DataTemplate >
                    <StackPanel Orientation="Horizontal">
                     </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

Drag and drop for first listbox:

private void helmet_MouseDown1(object sender, MouseButtonEventArgs e)
{
    _startPoint = e.GetPosition(null);


}

private void helmet_PreviewMouseMove(object sender, MouseEventArgs e)
{
    Point mousePos = e.GetPosition(null);
    Vector diff = _startPoint - mousePos;
    if (e.LeftButton == MouseButtonState.Pressed &&
  (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
   Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance))
    {

        var listBox = sender as ListBox;
        var listBoxItem = listBox.SelectedItem;

        DataObject dragData = new DataObject(_dropIdentifier, listBoxItem);
        DragDrop.DoDragDrop(listBox, dragData, DragDropEffects.Move);
    }

Answer 1

As MSDN says about enumeration DragDropEffects :

• All - The data is copied, removed from the drag source, and scrolled in the drop target.
• Copy - The data is copied to the drop target.
• Link - The data from the drag source is linked to the drop target.
• Move - The data from the drag source is moved to the drop target.
• None - The drop target does not accept the data.
• Scroll - Scrolling is about to start or is currently occurring in the drop target.

In order to just copy items you should just change the value DragDropEffects from Move to Copy :

private void helmet_PreviewMouseMove(object sender, MouseEventArgs e)
{
    //the code omitted for the brevity
    if (e.LeftButton == MouseButtonState.Pressed &&
  (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
   Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance))
    {    
        //the code omitted for the brevity
        DragDrop.DoDragDrop(listBox, dragData, DragDropEffects.Copy);
    }
}

XAML:

<ListBox x:Name="DropList" 
          Drop="DropList_Drop" 
          DragEnter="DropList_DragEnter" 
          AllowDrop="True" />

C#:

private void DropList_DragEnter(object sender, DragEventArgs e)
{
    if (!e.Data.GetDataPresent("myFormat") ||
        sender == e.Source)
    {
        e.Effects = DragDropEffects.None;
    }
}

    private void DropList_Drop(object sender, DragEventArgs e)
{
    if (e.Data.GetDataPresent("myFormat"))
    {
        Contact contact = e.Data.GetData("myFormat") as Contact;
        ListView listView = sender as ListView;
        listView.Items.Add(contact);
    }
}