Darrent的學習筆記

參考別人的資料改寫了一篇Treeview 節點拖曳，因為我喝了茶就會睡不著，  所以又有了這篇。
我讓這Treeview除了移動之外，也可以複製(按住Ctrl)、刪除(按Delete)

    public partial class Form1 : Form
    {
        bool controlKey;
        bool addNode;

        bool AddNode
        {
            set { addNode = value; }
            get { return addNode; }
        }

        bool ControlKey
        {
            set
            {
                controlKey = value;
                this.Cursor = value ? Cursors.Cross : Cursors.Default;
                if (!controlKey)
                    if (AddNode)
                        AddNode = false;
            }
            get { return controlKey; }
        }

        public Form1()
        {
            InitializeComponent();

            TreeNode treeNode1 = new TreeNode("Node1");
            TreeNode treeNode2 = new TreeNode("Node2");
            TreeNode treeNode3 = new TreeNode("Node3");
            TreeNode treeNode4 = new TreeNode("Node0", new TreeNode[] { treeNode1, treeNode2, treeNode3 });
            TreeNode treeNode5 = new TreeNode("Node6");
            TreeNode treeNode6 = new TreeNode("Node4", new TreeNode[] { treeNode5 });
            TreeNode treeNode7 = new TreeNode("Node5");
            this.treeView1.Nodes.AddRange(new TreeNode[] { treeNode4, treeNode6, treeNode7 });
            this.treeView1.ExpandAll();

            this.treeView1.DragDrop += new DragEventHandler(this.treeView1_DragDrop);
            this.treeView1.ItemDrag += new ItemDragEventHandler(treeView1_ItemDrag);
            this.treeView1.DragEnter += new DragEventHandler(treeView1_DragEnter);
        }

        void treeView1_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.Move;
            if (ControlKey)
                AddNode = true;
        }

        void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
        {
            DoDragDrop(e.Item, DragDropEffects.Move);
        }

        private void treeView1_DragDrop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false))
            {
                Point pt = ((TreeView)sender).PointToClient(new Point(e.X, e.Y));   //找出目前位置
                TreeNode destinationNode = ((TreeView)sender).GetNodeAt(pt);    //找出目的節點
                TreeNode moveNode = (e.Data.GetData("System.Windows.Forms.TreeNode")) as TreeNode;  //取出要移動的節點

                if (!AddNode)
                {
                    if (CheckForefather(moveNode, destinationNode)) //排除將父節點移到子節點的情況
                    {
                        MessageBox.Show("error!");
                        return;
                    }
                    moveNode.Remove();  //移去要移動的節點
                }
                destinationNode.Nodes.Add((TreeNode)moveNode.Clone());  //加到新節點之下
                destinationNode.ExpandAll();    //展開顯示
            }
        }        private bool CheckForefather(TreeNode fatherNode, TreeNode childNode)

        {
            if (fatherNode.Equals(childNode))
                return true;
            foreach (TreeNode tn in fatherNode.Nodes)
            {
                if (CheckForefather(tn, childNode))
                    return true;
            }
            return false;
        }

        private void treeView1_KeyDown(object sender, KeyEventArgs e)
        {
            if ((e.KeyCode & Keys.ControlKey) != 0)
                ControlKey = true;
        }

        private void treeView1_KeyUp(object sender, KeyEventArgs e)
        {
            if ((e.KeyCode & Keys.ControlKey) != 0)
                ControlKey = false;
            if (e.KeyCode == Keys.Delete)
            {
                TreeNode tn = ((TreeView)sender).SelectedNode;
                if (MessageBox.Show(String.Format("確定要刪除 {0} ?", tn.Text)) == DialogResult.OK)
                    tn.Remove();
            }
        }

    }

Tree.rar