I am trying to figure out how to move the items in a pre-populated listbox up and down via mouse drags.
I have looked at the Control.DoDragDrop method from microsoft's api, but I still can't get it to do anything.
I would appreciate any help since I am new to the visual studios environment.
i've tried create one using observablecollection, have a look
ObservableCollection<Emp> _empList = new ObservableCollection<Emp>();
public Window1()
{
InitializeComponent();
_empList .Add(new Emp("1", 22));
_empList .Add(new Emp("2", 18));
_empList .Add(new Emp("3", 29));
_empList .Add(new Emp("4", 9));
_empList .Add(new Emp("5", 29));
_empList .Add(new Emp("6", 9));
listbox1.DisplayMemberPath = "Name";
listbox1.ItemsSource = _empList;
Style itemContainerStyle = new Style(typeof(ListBoxItem));
itemContainerStyle.Setters.Add(new Setter(ListBoxItem.AllowDropProperty, true));
itemContainerStyle.Setters.Add(new EventSetter(ListBoxItem.PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(s_PreviewMouseLeftButtonDown)));
itemContainerStyle.Setters.Add(new EventSetter(ListBoxItem.DropEvent, new DragEventHandler(listbox1_Drop)));
listbox1.ItemContainerStyle = itemContainerStyle;
}
Drag and drop process
void s_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if (sender is ListBoxItem)
{
ListBoxItem draggedItem = sender as ListBoxItem;
DragDrop.DoDragDrop(draggedItem, draggedItem.DataContext, DragDropEffects.Move);
draggedItem.IsSelected = true;
}
}
void listbox1_Drop(object sender, DragEventArgs e)
{
Emp droppedData = e.Data.GetData(typeof(Emp)) as Emp;
Emp target = ((ListBoxItem)(sender)).DataContext as Emp;
int removedIdx = listbox1.Items.IndexOf(droppedData);
int targetIdx = listbox1.Items.IndexOf(target);
if (removedIdx < targetIdx)
{
_empList.Insert(targetIdx + 1, droppedData);
_empList.RemoveAt(removedIdx);
}
else
{
int remIdx = removedIdx+1;
if (_empList.Count + 1 > remIdx)
{
_empList.Insert(targetIdx, droppedData);
_empList.RemoveAt(remIdx);
}
}
}
Note:
PreviewMouseLeftButtonDown
event, the dragged item looks like not selected