一个 TreeView 的派生类: TreeViewEx 实现 NodeShowToolTip、NodeDoubleClick 事件

// playyuer@Microshaoft.com invent
//一个 TreeView 的派生类: TreeViewEx 实现 NodeShowToolTip、NodeDoubleClick 事件
//1.实现了 NodeShowToolTip 事件,结合键盘 Ctrl 键显示及设置 ToolTipText
//2.实现了 NodeDoubleClick 事件,可在调用中只响应"叶子"节点
//3.点击 TreeView 空白处不选中任何节点
//Class1.cs

namespace Microshaoft
{
    using System;
    using System.Windows.Forms;

    public class TreeViewEx : TreeView
{
        //委托类型
        public delegate void TreeViewExEventHandler(object sender, TreeViewExEventArgs e);

        //事件
        public event TreeViewExEventHandler NodeDoubleClick;
        public event TreeViewExEventHandler NodeShowToolTip;

        private ToolTip toolTip;

        public TreeViewEx()
{
            toolTip = new ToolTip();
            this.toolTip.InitialDelay = 300;
            this.toolTip.ReshowDelay = 0;
        }

        private void OnNodeDoubleClick(TreeNode xx)
{
            if (this.NodeDoubleClick != null)
{
                this.NodeDoubleClick(this, new TreeViewExEventArgs(xx));
            }
        }

        private void OnNodeShowToolTip(TreeNode xx, ToolTip yy)
{
            if (this.NodeShowToolTip != null)
{
                if ((xx != null) && (this.toolTip != null))
{
                    this.NodeShowToolTip(this, new TreeViewExEventArgs(xx, this.toolTip));
                }
            }
        }

        protected override void OnDoubleClick(EventArgs e)
{
            if (this.SelectedNode != null)
{
                this.OnNodeDoubleClick(this.SelectedNode);
            }
            base.OnDoubleClick(e);
        }

        protected override void OnClick(EventArgs e)
{
            if (this.GetNodeAt(TreeView.MousePosition.X, TreeView.MousePosition.Y) == null)
{
                this.SelectedNode = null;
            }
            base.OnClick(e);
        }

        protected override void OnMouseDown(MouseEventArgs e)
{
            if (this.GetNodeAt(e.X, e.Y) == null)
{
                this.SelectedNode = null;
            }
            base.OnMouseDown(e);
        }

        //用于保存上次节点,以判断是否更新 ToolTiptext
        private TreeNode LastTreeNode;

        protected override void OnMouseMove(MouseEventArgs e)
{
            this.Cursor = Cursors.Default;
            TreeNode treeNode;
            treeNode = this.GetNodeAt(e.X, e.Y);
            if (treeNode != null)
{
                if ((Control.ModifierKeys & Keys.Control) != 0)
{
                    this.Cursor = Cursors.Hand;
                    if (LastTreeNode == null | treeNode != LastTreeNode)
{
                        LastTreeNode = treeNode;
                        //this.toolTip.Active = false;
                        this.OnNodeShowToolTip(treeNode, this.toolTip);
                        this.toolTip.Active = true;
                        Console.WriteLine(treeNode.Text);
                    }
                }
                else
{
                    this.Cursor = Cursors.Default;
                    this.toolTip.Active = false;
                }
            }
            else
{
                this.Cursor = Cursors.Default;
                this.toolTip.Active = false;
            }
            base.OnMouseMove(e);
        }
    }

    public class TreeViewExEventArgs : EventArgs
{
        private string m_ToolTipText;
        private ToolTip m_NodeToolTip;
        private TreeNode m_SelectedNode;
        private TreeNode m_Node;

        public TreeViewExEventArgs(TreeNode SelectedNode)
{
            this.m_SelectedNode = SelectedNode;
        }

        public TreeViewExEventArgs(TreeNode Node, ToolTip NodeToolTip)
{
            this.m_NodeToolTip = NodeToolTip;
            this.m_Node = Node;
        }

        public TreeViewExEventArgs(TreeNode Node, string ToolTipText)
{
            this.m_ToolTipText = ToolTipText;
        }

        public TreeNode SelectedNode
{
            get
{
                return this.m_SelectedNode;
            }
        }

        public string ToolTipText
{
            get
{
                return this.ToolTipText;
            }
            set
{
                m_ToolTipText = value;
            }
        }

        public TreeNode Node
{
            get
{
                return this.m_Node;
            }
        }

        public ToolTip NodeToolTip
{
            get
{
                return this.m_NodeToolTip;
            }
        }
    }

    public class TreeNodeEx : TreeNode
{
        public int GetLevel()
{
            int i = 0;
            TreeNode xx = this.Parent;
            while ((xx = xx.Parent) != null)
{
                i++;
            }
            return i;
        }
    }
}

//using System;


//测试====================

namespace WindowsApplication1
{
    using System;
    using System.Drawing;
    using System.ComponentModel;
    using System.Windows.Forms;

    using Microshaoft;


    /// Form1 的摘要说明。
    /// </summary>
    public class Form1 : Form
{
        private Button button1;


        /// 必需的设计器变量。
        /// </summary>
        private Container components = null;

        public Form1()
{
            //
            // Windows 窗体设计器支持所必需的
            //
            InitializeComponent();

            //
            // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
            //
        }


        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose(bool disposing)
{
            if (disposing)
{
                if (components != null)
{
                    components.Dispose();
                }
            }
            base.Dispose(disposing);
        }




        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
{
            this.button1 = new Button();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new Point(96, 112);
            this.button1.Name = "button1";
            this.button1.Size = new Size(88, 32);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.Click += new EventHandler(this.button1_Click);
            // 
            // Form1
            // 
            this.AutoScaleBaseSize = new Size(6, 14);
            this.ClientSize = new Size(292, 273);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new EventHandler(this.Form1_Load);
            this.ResumeLayout(false);

        }

        #endregion


        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        private static void Main()
{
            Application.Run(new Form1());
        }

        //=================================================================
        //调用示例
        private TreeViewEx treeViewEx1;

        private void Form1_Load(object sender, EventArgs e)
{
            treeViewEx1 = new TreeViewEx();
            this.Controls.Add(treeViewEx1);
            treeViewEx1.HideSelection = false;
            treeViewEx1.NodeDoubleClick += new TreeViewEx.TreeViewExEventHandler(treeViewEx1_NodeDoubleClick);
            treeViewEx1.NodeShowToolTip += new TreeViewEx.TreeViewExEventHandler(this.treeViewEx1_NodeShowToolTip);
            treeViewEx1.Nodes.AddRange(new TreeNode[]
{
                    new TreeNode("Root",
                                 new TreeNode[]
{
                                         new TreeNode("a"), new TreeNode("b")
                                     }
                        ),
                    new TreeNode("Root1",
                                 new TreeNode[]
{
                                         new TreeNode("a1"), new TreeNode("b1")
                                     }
                        )
                }
                );
        }

        public void treeViewEx1_NodeShowToolTip(object sender, TreeViewExEventArgs e)
{
            e.NodeToolTip.SetToolTip(this.treeViewEx1, "ToolTipText: [" + e.Node.Text + "]");
            //e.NodeToolTip.SetToolTip (this.treeViewEx1,"ToolTipText: [" + e.Node.Text + "]" );
            //Console.WriteLine(e.Node.Text);
        }

        private void treeViewEx1_NodeDoubleClick(object sender, TreeViewExEventArgs e)
{
            if (e.SelectedNode.GetNodeCount(true) == 0)
                MessageBox.Show(e.SelectedNode.Text);
        }

        private void button1_Click(object sender, EventArgs e)
{
        }
    }
}