将treeview控件内容导出图片

　　项目中有一项需求，需要将项目中的treeview控件展示的树状结构直接导成一张图片。网上方法很多，但很多都是屏幕截屏，我的解决思路是新建一个用户控件，将主窗体的Treeview的数据传给用户控件（不要直接用treeview做参数，可能会有问题），控件中将TreeView放到一个panel中，根据tree的节点深度和叶子节点个数来调整panel的高度和宽度，然后使用panel内置方法导出即可。具体步骤如下：

　　1. 新建用户控件   控件主要代码如下

    public partial class uc_outputtree : UserControl
    {
        private TreeView treeoutput;
        private Panel panelcontent;

        public uc_outputtree(TreeNode node)
        {
            InitializeComponent();
            this.treeoutput = new TreeView();
            treeoutput.Nodes.Clear();
            treeoutput.Nodes.Add((TreeNode)node);
            treeoutput.ExpandAll();
            treeoutput.Dock = DockStyle.Fill;

            this.panelcontent = new Panel();
            this.panelcontent.Location = new System.Drawing.Point(3, 3);
            this.panelcontent.Height = tree.getTotalLeafNum(node) * 20 + 50;
            this.panelcontent.Width = tree.getDeepthTree(node) * 50 + 100;
            this.panelcontent.Controls.Add(this.treeoutput);
        }

        /// <summary>
        /// 定义委托
        /// </summary>
        public delegate void UCeventOutPut();
        /// <summary>
        /// 事件
        /// </summary>
        public event UCeventOutPut UCOutPutEvent;

        public void TreeOutPut()
        {
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            saveFileDialog.FilterIndex = 0;
            saveFileDialog.RestoreDirectory = true;
            saveFileDialog.CreatePrompt = true;
            saveFileDialog.Title = "导出文件到";

            DateTime now = DateTime.Now;
            saveFileDialog.FileName = now.Year.ToString().PadLeft(2) + now.Month.ToString().PadLeft(2, '0')
        + now.Day.ToString().PadLeft(2, '0') + "-" + now.Hour.ToString().PadLeft(2, '0')
        + now.Minute.ToString().PadLeft(2, '0') + now.Second.ToString().PadLeft(2, '0') + "_datoutput.jpg";

            saveFileDialog.Filter = "Jpg Files|*.jpg";
            if (saveFileDialog.ShowDialog() == DialogResult.OK)
            {
                Rectangle rect = new Rectangle(0, 0, this.treeoutput.ClientRectangle.Width, this.treeoutput.ClientRectangle.Height);
                using (Bitmap bmp = new Bitmap(rect.Width, rect.Height, PixelFormat.Format16bppRgb555))
                {
                    this.panelcontent.DrawToBitmap(bmp, rect);
                    bmp.Save(saveFileDialog.FileName, ImageFormat.Jpeg);

                    UCOutPutEvent();
                }
            }
        }
    }

　　2. 主窗体引用控件

       internal void DataOutPutPic()
        {
            uc_outputtree uc_outputtree = new uc_outputtree((TreeNode)this.Tree_Network.Nodes[0].Clone());
            uc_outputtree.UCOutPutEvent += new uc_outputtree.UCeventOutPut(ucExport_UCOutPutEvent);
            uc_outputtree.TreeOutPut();
            uc_outputtree.Dispose();
        }

        void ucExport_UCOutPutEvent()
        {
            MessageBox.Show("导出完成");
        }

       3. tree的算法

        /// <summary>
        /// 获取节点深度
         /// </summary>
        /// <param name="treenode"></param>
        /// <returns></returns>
        public static int getDeepthTree(TreeNode treenode)
        {
            int deepth = 0;
            TreeNode rt = treenode;

            if (rt.Nodes.Count > 0)
            {
                foreach (TreeNode tr in rt.Nodes)
                {
                    int temp = 1 + getDeepthTree(tr);
                    if (temp > deepth)
                    {
                        deepth = temp;
                    }
                }
            }
            else
            {
                deepth = 1;
            }

            return deepth;
        }

        /// <summary>
        /// 获取所有叶子节点个数
         /// </summary>
        /// <param name="t"></param>
        /// <returns></returns>
        public static int getTotalLeafNum(TreeNode t)
        {
            int num = 0;
            if (t.Nodes.Count > 0)
            {
                foreach (TreeNode tr in t.Nodes)
                {
                    num += getTotalLeafNum(tr);
                }
            }
            else
            {
                num = 1;
            }
            return num;
        }