using System;

using System.Windows.Forms;

using System.Drawing;

using System.Runtime.InteropServices;

namespace SenseTreeView

{

    public class SenseTreeView : TreeView

    {

        #region 控件属性

        //显示字体

        private Font _NodeFont;

        public Font NodeFont

        {

            get

            {

                return _NodeFont;

            }

            set

            {

                _NodeFont = value;

            }

        }

        //选择TreeView TreeNode时的背景色

        private Brush _BackgrountBrush;

        public Brush BackgroundBrush

        {

            get

            {

                return _BackgrountBrush;

            }

            set

            {

                _BackgrountBrush = value;

            }

        }

        //选择TreeView TreeNode时背景色的边框画笔

        private Pen _BackgroundPen;

        public Pen BackgroundPen

        {

            get

            {

                return _BackgroundPen;

            }

            set

            {

                _BackgroundPen = value;

            }

        }

        //TreeView中TreeNode展开时的节点显示图标，

        private Image _NodeExpandedImage;

        public Image NodeExpandedImage

        {

            get

            {

                return _NodeExpandedImage;

            }

            set

            {

                _NodeExpandedImage = value;

            }

        }

        //TreeView中TreeNode合拢时的节点显示图标

        private Image _NodeCollapseImage;

        public Image NodeCollapseImage

        {

            get

            {

                return _NodeCollapseImage;

            }

            set

            {

                _NodeCollapseImage = value;

            }

        }

        //TreeView中TreeNode的节点显示图标的大小

        private Size _NodeImageSize;

        public Size NodeImageSize

        {

            get

            {

                return _NodeImageSize;

            }

            set

            {

                _NodeImageSize = value;

            }

        }

        //节点显示图标离左边界的位置

        private int _NodeOffset;

        public int NodeOffset

        {

            get

            {

                return _NodeOffset;

            }

            set

            {

                _NodeOffset = value;

            }

        }

        #endregion

        #region 构造函数

        public SenseTreeView()

        {

            //设置窗体Style

            //this.SetStyle(ControlStyles.UserPaint, true);               //支持用户重绘窗体

            //this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);    //在内存中先绘制界面

            //this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);   //双缓冲，防止绘制时抖动

            //this.SetStyle(ControlStyles.DoubleBuffer, true);            //双缓冲，防止绘制时抖动

            //this.UpdateStyles();

            //不显示树形节点显示连接线

            this.ShowLines = false;

            //设置绘制TreeNode的模式

            this.DrawMode = TreeViewDrawMode.OwnerDrawAll;

            //不显示TreeNode前的“+”和“-”按钮

            this.ShowPlusMinus = false;

            //不支持CheckedBox

            this.CheckBoxes = false;

            //设置TreeNode的行高

            SendMessage(this.Handle, TVM_SETITEMHEIGHT, , );

            //设置默认BackgroundBrush

            BackgroundBrush = new SolidBrush(Color.FromArgb(, Color.FromArgb(, , )));

            //设置默认BackgroundPen

            BackgroundPen = new Pen(Color.FromArgb(, , ), );

            //设置默认NodeFont

            NodeFont = new Font("宋体", , FontStyle.Regular);

            //设置默认节点显示图标及Size

            NodeExpandedImage = null;

            NodeCollapseImage = null;

            NodeImageSize = new Size(, );

            //设置默认节点显示图标便宜位置

            NodeOffset = ;

        }

        #endregion

        #region 节点绘制函数

        //绘制TreeView树中TreeNode

        protected override void OnDrawNode(DrawTreeNodeEventArgs e)

        {

            TreeNode tn = e.Node as TreeNode;

            if (tn == null)

            {

                return;

            }

            //设置Image绘制Rectangle

            Point pt = new Point(tn.Bounds.X + NodeOffset, tn.Bounds.Y);

            Rectangle rt = new Rectangle(pt, NodeImageSize);

            if ((e.State & TreeNodeStates.Selected) != )

            {

                //绘制TreeNode选择后的背景框

                e.Graphics.FillRectangle(BackgroundBrush, , tn.Bounds.Y, this.Width - , tn.Bounds.Height - );

                //绘制TreeNode选择后的边框线条

                e.Graphics.DrawRectangle(BackgroundPen, , tn.Bounds.Y, this.Width - , tn.Bounds.Height - );

            }

            //绘制节点图片

            if (NodeExpandedImage != null && NodeCollapseImage != null)

            {

                if (tn.Nodes.Count != )

                {

                    if (tn.IsExpanded == true)

                    {

                        e.Graphics.DrawImage(NodeExpandedImage, rt);

                    }

                    else

                    {

                        e.Graphics.DrawImage(NodeCollapseImage, rt);

                    }

                }

                rt.X += ;

            }

            //绘制节点自身图片

            if (e.Node.SelectedImageIndex != - && this.ImageList != null)

            {

                rt.X += ;

                e.Graphics.DrawImage(this.ImageList.Images[e.Node.SelectedImageIndex], rt);

            }

            //绘制节点的文本

            rt.X += ;

            rt.Y += ;

            rt.Width = this.Width - rt.X;

            e.Graphics.DrawString(e.Node.Text, NodeFont, Brushes.Black, rt);

        }

        #endregion

        #region 鼠标消息响应函数

        //响应鼠标按下消息

        protected override void OnMouseDown(MouseEventArgs e)

        {

            TreeNode clickedNode = this.GetNodeAt(e.X, e.Y);

            if (clickedNode != null && NodeBounds(clickedNode).Contains(e.X, e.Y))

            {

                this.SelectedNode = clickedNode;

            }

        }

        //响应鼠标双击消息

        protected override void OnMouseDoubleClick(MouseEventArgs e)

        {

            TreeNode clickedNode = this.GetNodeAt(e.X, e.Y);

            if (clickedNode != null && NodeBounds(clickedNode).Contains(e.X, e.Y))

            {

                this.SelectedNode = clickedNode;

                //判断节点的状态

                if (clickedNode.Nodes.Count != )

                {

                    if (clickedNode.IsExpanded)

                    {

                        clickedNode.Collapse();

                    }

                    else

                    {

                        clickedNode.Expand();

                    }

                }

            }

        }

        #endregion

        #region 私有函数

        //返回TreeView中TreeNode的整行区域

        private Rectangle NodeBounds(TreeNode node)

        {

            // Set the return value to the normal node bounds.

            Rectangle bounds = node.Bounds;

            //if (node.Tag != null)

            //{

            //    // Retrieve a Graphics object from the TreeView handle

            //    // and use it to calculate the display width of the tag.

            //    Graphics g = this.CreateGraphics();

            //    int tagWidth = (int)g.MeasureString(node.Tag.ToString(), NodeFont).Width + 6;

            //    // Adjust the node bounds using the calculated value.

            //    bounds.Offset(tagWidth / 2, 0);

            //    bounds = Rectangle.Inflate(bounds, tagWidth / 2, 0);

            //    g.Dispose();

            //}

            bounds.Width = this.Width;

            return bounds;

        }

        #endregion

        #region 引用函数

        const int TV_FRIST = 0x1100;

        const int TVM_SETITEMHEIGHT = TV_FRIST + ;

        [DllImport("user32.dll", CharSet = CharSet.Auto)]

        private static extern IntPtr SendMessage(IntPtr hWnd, int nMsg, int wParam, int Param);

        #endregion

    }

}

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using SenseTreeView.Properties;

namespace SenseTreeView

{

    public partial class Form1 : Form

    {

        private SenseTreeView stv;

        public Form1()

        {

            InitializeComponent();

            // Create and initialize the TreeView control.

            stv = new SenseTreeView();

            stv.Dock = DockStyle.Left;

            stv.BackColor = Color.White;

            //stv.CheckBoxes = true;

            stv.Width = ;

            ImageList imagelist = new ImageList();

            imagelist.Images.Add(Resources._1264);

            imagelist.Images.Add(Resources._1265);

            imagelist.Images.Add(Resources._1268);

            stv.ImageList = imagelist;

            stv.NodeExpandedImage = Resources.UnSelect;

            stv.NodeCollapseImage = Resources.IsSelect;

            // Add nodes to the TreeView control.

            for (int x = ; x < ; ++x)

            {

                // Add a root node to the TreeView control.

                TreeNode node = new TreeNode("中华人民共和国");

                node.SelectedImageIndex = ;

                for (int y = ; y < ; ++y)

                {

                    // Add a child node to the root node.

                    TreeNode tn = new TreeNode("Subtask");

                    tn.SelectedImageIndex = ;

                    node.Nodes.Add(tn);

                }

                stv.Nodes.Add(node);

            }

            stv.ExpandAll();

            // Initialize the form and add the TreeView control to it.

            this.Controls.Add(stv);

        }

    }

}