Question

I have two TreeView which are in seperate forms.

• treeView1
• treeView2

I implemented a Drag and Drop functionality so that I can drag from on tree to another and it works fine with the code I found here where I have to handle 3 events.

The thing is the setup of my windows looks like this :

As you can see, Window2 hides my Window1 and it’s on purpose and needs to stay like this. The problem is my Drag and Drop is from Window2 to Window1 so I can’t specify a destination node. Is there a way to simply drop into a TreeView without any destination node and say create a parent node next to the other ones ?

---

Links die examples don’t :

private void Form1_Load(object sender, System.EventArgs e)
{
    this.treeView1.ItemDrag += new System.Windows.Forms.ItemDragEventHandler(this.treeView_ItemDrag);
    this.treeView2.ItemDrag += new System.Windows.Forms.ItemDragEventHandler(this.treeView_ItemDrag);
    this.treeView1.DragEnter += new System.Windows.Forms.DragEventHandler(this.treeView_DragEnter);
    this.treeView2.DragEnter += new System.Windows.Forms.DragEventHandler(this.treeView_DragEnter);
    this.treeView1.DragDrop += new System.Windows.Forms.DragEventHandler(this.treeView_DragDrop);
    this.treeView2.DragDrop += new System.Windows.Forms.DragEventHandler(this.treeView_DragDrop);   
}

private void treeView_ItemDrag(object sender,
        System.Windows.Forms.ItemDragEventArgs e)
{
    DoDragDrop(e.Item, DragDropEffects.Move);
}

private void treeView_DragEnter(object sender,
        System.Windows.Forms.DragEventArgs e)
{
    e.Effect = DragDropEffects.Move;
}

private void treeView_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
{
    TreeNode NewNode;

    if(e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false))
    {
        Point pt = ((TreeView)sender).PointToClient(new Point(e.X, e.Y));
        TreeNode DestinationNode = ((TreeView)sender).GetNodeAt(pt);
            NewNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
        if(DestinationNode.TreeView != NewNode.TreeView)
        {     
            DestinationNode.Nodes.Add((TreeNode) NewNode.Clone());
            DestinationNode.Expand();
            //Remove Original Node
            NewNode.Remove();
        }
    }
}

Answer 1

Change treeview_dragdrop of both forms to the following:

   private void treeView_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
    {
        TreeNode NewNode;

        if(e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false))
        {
            NewNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
            if (!(sender as TreeView).Nodes.Contains(NewNode))//Edit: add this if you don't want to add the same one again.
            {    
                 (sender as TreeView).Nodes.Add((TreeNode) NewNode.Clone());                 
                 NewNode.Remove(); //Edit: add this if you want to remove original one.
            } 
        }
    }