关于两个TreeView节点间连线

        private void treeView1_DragEnter(object sender, DragEventArgs e)
        {
            if ( e.Data.GetDataPresent("System.Windows.Forms.TreeNode") )
            {
                e.Effect = DragDropEffects.Copy;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }

        private void treeView1_DragDrop(object sender, DragEventArgs e)
        {
            StartTV = ( (TreeView) sender );
            TreeNode TempNode = (TreeNode) e.Data.GetData("System.Windows.Forms.TreeNode");
            if ( e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false) )
            {
                Point pt;
                TreeNode DestNode;
                pt = ( (TreeView) sender ).PointToClient(new Point(e.X, e.Y));
                DestNode = ( (TreeView) sender ).GetNodeAt(pt);
                treeView1.SelectedNode = DestNode;
                if ( StartTV.Left > EndTV.Left )
                    DrawLine(StartTV, EndTV);
                else
                    DrawLine(EndTV, StartTV);
            }
        }

        private void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
        {
            EndTV = ( (TreeView) sender );
            TreeNode SelectNode = new TreeNode();
            foreach ( TreeNode nodes in treeView1.Nodes )
            {
                foreach ( TreeNode node in nodes.Nodes )
                {
                    if ( node.ToString().Trim() == e.Item.ToString().Trim() )
                    {
                        SelectNode = node;
                        break;
                    }
                }
            }
            treeView1.SelectedNode = SelectNode;
            treeView1.DoDragDrop(treeView1.SelectedNode, DragDropEffects.Copy);
        }

        private void treeView2_DragDrop(object sender, DragEventArgs e)
        {
            StartTV = ( (TreeView) sender );
            TreeNode TempNode = (TreeNode) e.Data.GetData("System.Windows.Forms.TreeNode");
            if ( e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false) )
            {
                Point pt;
                TreeNode DestNode;
                pt = ( (TreeView) sender ).PointToClient(new Point(e.X, e.Y));
                DestNode = ( (TreeView) sender ).GetNodeAt(pt);
                treeView2.SelectedNode = DestNode;
                if ( StartTV.Left > EndTV.Left )
                    DrawLine(StartTV, EndTV);
                else
                    DrawLine(EndTV, StartTV);
            }
        }

        private void treeView2_DragEnter(object sender, DragEventArgs e)
        {
            if ( e.Data.GetDataPresent("System.Windows.Forms.TreeNode") )
            {
                e.Effect = DragDropEffects.Copy;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }

        private void treeView2_ItemDrag(object sender, ItemDragEventArgs e)
        {
            EndTV = ( (TreeView) sender );
            TreeNode SelectNode = new TreeNode();
            foreach ( TreeNode nodes in treeView2.Nodes )
            {
                foreach ( TreeNode node in nodes.Nodes )
                {
                    if ( node.ToString().Trim() == e.Item.ToString().Trim() )
                    {
                        SelectNode = node;
                        break;
                    }
                }
            }
            treeView2.SelectedNode = SelectNode;
            treeView2.DoDragDrop(treeView2.SelectedNode, DragDropEffects.Copy);
        }

 

private void DrawLine(TreeView TV1, TreeView TV2)
        {
            TreeNode tn1 = TV1.SelectedNode;
            TreeNode tn2 = TV2.SelectedNode;

            Point p11;
            p11 = new Point(tn1.Bounds.Left, tn1.Bounds.Top + ( tn1.Bounds.Bottom - tn1.Bounds.Top ) / 2);
            Point p12;
            p12 = new Point(-10, tn1.Bounds.Top + ( tn1.Bounds.Bottom - tn1.Bounds.Top ) / 2);           

            Point p21;
            p21 = new Point(tn2.Bounds.Right, tn2.Bounds.Top + ( tn2.Bounds.Bottom - tn2.Bounds.Top ) / 2);
            Point p22;
            p22 = new Point(tn2.Bounds.Right + tn2.Bounds.Width + tn2.Bounds.Left, tn2.Bounds.Top + ( tn2.Bounds.Bottom - tn2.Bounds.Top ) / 2);

            Point p31;
            Point p32;
            p31 = new Point(TV2.Width + TV2.Left, TV2.Top + tn2.Bounds.Top + ( tn2.Bounds.Bottom - tn2.Bounds.Top ) / 2);
            p32 = new Point(TV1.Left, TV1.Top + tn1.Bounds.Top + ( tn1.Bounds.Bottom - tn1.Bounds.Top ) / 2);

            TreeView[] tv = new TreeView[] { TV1,TV2};
            lTV.Add(tv);
            Point[] p = new Point[] { p11, p12, p21, p22, p31, p32 };
            lp.Add(p);
            DrawLine();
        }

        private void DrawLine()
        {
            this.Refresh();
            for ( int i = 0; i < lp.Count; i++ )
            {
                TreeView[] tt = lTV[i];
                Point[] linePoint = lp[i];
                Graphics g1 = tt[0].CreateGraphics();
                g1.DrawLine(new Pen(Color.Red), linePoint[0], linePoint[1]);
                g1.SmoothingMode = SmoothingMode.HighQuality;

                Graphics g2 = tt[1].CreateGraphics();
                g2.DrawLine(new Pen(Color.Red), linePoint[2], linePoint[3]);
                g2.SmoothingMode = SmoothingMode.HighQuality;

                Graphics g3 = this.groupBox1.CreateGraphics();
                g3.DrawLine(new Pen(Color.Red), linePoint[4], linePoint[5]);
                g3.SmoothingMode = SmoothingMode.HighQuality;
            }
        }

结果如图：想请教高手怎样实现两点间之间画线，同时线段不要出现锯齿