Question

OK, first for context look at the Windows desktop; You can take items (folders, files) on the desktop and drag them around to different places and they ‘stay’ where you dragged them. This seems to be a pretty useful feature to offer users so as to allow them to create their own ‘groupings’ of items.

My question is thus: Is there a control in .NET that approximates this behavior with a collection of items?

I’m thinking something like a listview in ‘LargeIcon’ mode, but it allows you to drag the icons around to different places inside the control.

Answer 1

You can do this with a standard ListView control by implementing drag-and-drop. Here’s a sample control that does this:

using System; using System.Drawing; using System.Windows.Forms;  public class MyListView : ListView {   private Point mItemStartPos;   private Point mMouseStartPos;    public MyListView() {     this.AllowDrop = true;     this.View = View.LargeIcon;     this.AutoArrange = false;     this.DoubleBuffered = true;   }    protected override void OnDragEnter(DragEventArgs e) {     if (e.Data.GetData(typeof(ListViewItem)) != null) e.Effect = DragDropEffects.Move;   }   protected override void OnItemDrag(ItemDragEventArgs e) {     // Start dragging     ListViewItem item = e.Item as ListViewItem;     mItemStartPos = item.Position;     mMouseStartPos = Control.MousePosition;     this.DoDragDrop(item, DragDropEffects.Move);   }   protected override void OnDragOver(DragEventArgs e) {     // Move icon     ListViewItem item = e.Data.GetData(typeof(ListViewItem)) as ListViewItem;     if (item != null) {       Point mousePos = Control.MousePosition;       item.Position = new Point(mItemStartPos.X + mousePos.X - mMouseStartPos.X,           mItemStartPos.Y + mousePos.Y - mMouseStartPos.Y);     }   } }