private void TreeView_DragOver(object sender, DragEventArgs e)
{
TreeView tree = (TreeView)sender;
Point targetPoint = tree.PointToClient(new Point(e.X, e.Y));
TreeNode targetNode = tree.GetNodeAt(targetPoint);
DragDropInformation info = (DragDropInformation)e.Data.GetData(typeof(DragDropInformation));
if (info == null)
{
return;
}
TreeViewDragDropHelper.ImageList_DragMove(targetPoint.X, targetPoint.Y);
//TreeViewDragDropHelper.ImageList_DragMove(e.X, e.Y);
TreeNode sourceNode = info.SourceNode;
if (info.Client.IsDropAllowed(sourceNode, targetNode))
{
TreeViewDragDropHelper.ImageList_DragShowNolock(false);
tree.SelectedNode = targetNode;
e.Effect = e.AllowedEffect;
TreeViewDragDropHelper.ImageList_DragShowNolock(true);
}
else
{
TreeViewDragDropHelper.ImageList_DragShowNolock(false);
tree.SelectedNode = sourceNode;
e.Effect = DragDropEffects.None;
TreeViewDragDropHelper.ImageList_DragShowNolock(true);
}
}
private void ScrollDown(Point pt)
{
TreeNode visibleNode = this.TreeView.GetNodeAt(pt);
if (visibleNode == null)
{
return;
}
TreeNode showNode = visibleNode.NextVisibleNode;
if (showNode == null)
{
showNode = visibleNode.NextNode;
if (showNode == null)
{
showNode = visibleNode.Parent;
if (showNode != null)
{
showNode = showNode.NextNode;
}
}
}
if (showNode != null)
{
TreeViewDragDropHelper.ImageList_DragShowNolock(false);
showNode.EnsureVisible();
this.TreeView.Invalidate();
TreeViewDragDropHelper.ImageList_DragShowNolock(true);
}
}
private void TreeView_DragEnter(object sender, DragEventArgs e)
{
e.Effect = e.AllowedEffect;
TreeView tree = (TreeView)sender;
Point targetPoint = tree.PointToClient(new Point(e.X, e.Y));
TreeViewDragDropHelper.ImageList_DragEnter(((TreeView)sender).Handle, targetPoint.X, targetPoint.Y);
//this.ScrollTimer.Enabled = true;
}
public void DoDragDrop(IDragDropClient client, TreeNode node, DragDropEffects effects)
{
if (client == null)
{
throw new ArgumentNullException("client");
}
if (node == null)
{
throw new ArgumentNullException("node");
}
using (ImageList imgList = this.CreateImageList(node))
{
TreeViewDragDropHelper.ImageList_BeginDrag(imgList.Handle, 0, 0, 0);
try
{
node.TreeView.DragDrop += new DragEventHandler(this.TreeView_DragDrop);
node.TreeView.DragEnter += new DragEventHandler(this.TreeView_DragEnter);
node.TreeView.DragLeave += new EventHandler(this.TreeView_DragLeave);
node.TreeView.DragOver += new DragEventHandler(this.TreeView_DragOver);
try
{
using (new ScrollHelper(node.TreeView))
node.TreeView.DoDragDrop(new DragDropInformation(node, client), effects);
}
finally
{
TreeView tree = node.TreeView;
if (tree != null)
{
tree.DragDrop -= new DragEventHandler(this.TreeView_DragDrop);
tree.DragEnter -= new DragEventHandler(this.TreeView_DragEnter);
tree.DragLeave -= new EventHandler(this.TreeView_DragLeave);
tree.DragOver -= new DragEventHandler(this.TreeView_DragOver);
}
}
}
finally
{
TreeViewDragDropHelper.ImageList_EndDrag();
}
}
}
private void TreeView_DragLeave(object sender, EventArgs e)
{
//this.ScrollTimer.Enabled = false;
TreeViewDragDropHelper.ImageList_DragLeave(((TreeView)sender).Handle);
}
