/***********************
* 说明：主界面左菜单树
* 创建人：龚宇超
* 创建日期：2018-04-25
* 修改人：
* 修改日期：
* 修改备注：
* 版本：1.0.0.0
***********************/
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace Lskj.Main.Control
{
    public partial class TreeViewCustom : UserControl
    {
        #region 公有属性
        /// <summary>
        /// 父节点字段
        /// </summary>
        public string ParentField;
        /// <summary>
        /// 显示节点文本字段
        /// </summary>
        public string TextField;
        /// <summary>
        /// 父节点关联子节点位数
        /// </summary>
        public int ParentKeyLength;
        /// <summary>
        /// 左侧菜单点击回调
        /// </summary>
        /// <param name="after">The after.</param>
        public delegate void ButtonClickEventHandler(Button after);
        /// <summary>
        /// 左侧菜单事件注册
        /// </summary>
        public ButtonClickEventHandler OnButtonClickEvent;
        /// <summary>
        /// 所有节点点击时都触发回调，默认保持原来的末级节点触发逻辑。
        /// </summary>
        public bool RaiseClickEventOnAllNodes;
        /// <summary>
        /// 默认显示所有节点。
        /// </summary>
        public bool ExpandAllNodes;
        /// <summary>
        /// 是否允许点击节点时展开/折叠子节点。
        /// </summary>
        public bool AllowNodeCollapse = true;
        /// <summary>
        /// 鼠标滑过节点时是否触发点击回调。
        /// </summary>
        public bool SwitchOnMouseMove;
        /// <summary>
        /// 使用旧版左侧菜单文字大小。
        /// </summary>
        public bool UseMenuBarTextStyle;
        /// <summary>
        /// 使用分组左侧菜单专用图片样式。
        /// </summary>
        public bool UseGroupTreeImageStyle;
        #endregion

        #region 私有属性
        /// <summary>
        /// 上次显示节点
        /// </summary>
        private string _lastTreeNode;
        /// <summary>
        /// 上次显示按钮ID
        /// </summary>
        private string _lastMenuId;
        /// 数据源
        /// </summary>
        private DataTable _dataSource;
        /// <summary>
        /// 缓存菜单，按照节点缓存
        /// </summary>
        private Dictionary<string, List<TreeNodeCustom>> _dicTreeNodes = new Dictionary<string, List<TreeNodeCustom>>();
        /// <summary>
        /// 缓存所有按钮
        /// </summary>
        private Dictionary<string, Button> _dicButtons = new Dictionary<string, Button>();
        /// <summary>
        /// 记录节点自身是否应显示，避免 Control.Visible 受父控件可见性影响。
        /// </summary>
        private HashSet<string> _visibleNodeValues = new HashSet<string>();
        /// <summary>
        /// 默认展开节点。
        /// </summary>
        private string _defaultExpandNodeValue;
        #endregion

        #region Api
        [DllImport("user32.dll")]
        public static extern int SendMessage(IntPtr hWnd, Int32 wMsg, bool wParam, Int32 lParam);

        private const int WM_SETREDRAW = 11;

        /// <summary>
        /// <para>说明：停止绘制</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        /// <param name="parent"></param>
        public static void SuspendDrawing(System.Windows.Forms.Control parent)
        {
            SendMessage(parent.Handle, WM_SETREDRAW, false, 0);
        }

        /// <summary>
        /// <para>说明：开始绘制</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        /// <param name="parent"></param>
        public static void ResumeDrawing(System.Windows.Forms.Control parent)
        {
            SendMessage(parent.Handle, WM_SETREDRAW, true, 0);
            parent.Refresh();
        }
        #endregion

        public TreeViewCustom()
        {
            InitializeComponent();
            this.plTreeView.Resize += (s, e) => ReflowTreeNodes();
        }

        protected override void WndProc(ref Message m)
        {
            if (m.Msg == 0x0014) return;
            base.WndProc(ref m);
        }

        /// <summary>
        /// <para>说明：检查是否包含父节点</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        /// <returns></returns>
        private List<TreeNodeCustom> getParentNodes(string parent)
        {
            string parentKey = parent.Length == ParentKeyLength ? parent : parent.Substring(0, parent.Length - ParentKeyLength);
            List<TreeNodeCustom> treeNodeList = new List<TreeNodeCustom>();

            if (_dicTreeNodes == null)
                _dicTreeNodes = new Dictionary<string, List<TreeNodeCustom>>();

            if (_dicTreeNodes.ContainsKey(parentKey))
            {
                treeNodeList = _dicTreeNodes[parentKey];
            }
            else
            {
                _dicTreeNodes.Add(parentKey, treeNodeList);
            }
            return treeNodeList;
        }
        /// <summary>
        /// <para>说明：加载菜单</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        public void SetDataSource(DataTable dtTable)
        {
            SetDataSource(dtTable, string.Empty);
        }

        /// <summary>
        /// 加载菜单并展开默认节点。
        /// </summary>
        public void SetDataSource(DataTable dtTable, string defaultExpandNodeValue)
        {
            int index = 1;
            this._dataSource = dtTable;
            this._lastTreeNode = null;
            this._lastMenuId = null;
            this._defaultExpandNodeValue = defaultExpandNodeValue;
            this._dicTreeNodes.Clear();
            this._dicButtons.Clear();
            this._visibleNodeValues.Clear();
            this.plTreeView.Controls.Clear();
            if (_dataSource == null || _dataSource.Rows.Count == 0) return;
            var leftItems = _dataSource.Rows.Cast<DataRow>().OrderBy(n => n[ParentField] + "");
            foreach (DataRow item in leftItems)
            {
                string nodeValue = item[ParentField] + "";
                int length = nodeValue.Length;
                TreeNodeCustom treeNode = new TreeNodeCustom();
                treeNode.Dock = DockStyle.None;
                treeNode.Anchor = AnchorStyles.Left | AnchorStyles.Top | AnchorStyles.Right;
                treeNode.Tag = nodeValue;
                treeNode.TabIndex = index;
                if (UseMenuBarTextStyle)
                {
                    treeNode.Height = 44;
                }

                SetNodeDefaultStyle(treeNode.btnTreeNode, GetNodeLevel(nodeValue));

                treeNode.btnTreeNode.Name = index + "";
                treeNode.btnTreeNode.Text = item[TextField] + "";
                treeNode.btnTreeNode.Tag = item;
                treeNode.btnTreeNode.Click += new EventHandler(btnTreeNode_Click);
                treeNode.btnTreeNode.MouseMove += new MouseEventHandler(btnTreeNode_MouseMove);
                treeNode.btnTreeNode.MouseLeave += new EventHandler(btnTreeNode_MouseLeave);

                plTreeView.Controls.Add(treeNode);
                _dicButtons.Add(index + "", treeNode.btnTreeNode);

                List<TreeNodeCustom> parentNodes = getParentNodes(nodeValue);
                parentNodes.Add(treeNode);
                // 隐藏需要放在添加后，否则出现顺序错乱
                SetNodeVisibleState(treeNode, ExpandAllNodes || length == ParentKeyLength || IsDefaultExpandedChildNode(nodeValue));
                index++;
            }
            RefreshNodeStyles();
            ReflowTreeNodes();
        }

        /// <summary>
        /// 展开指定节点。
        /// </summary>
        public void ExpandNode(string nodeValue)
        {
            if (string.IsNullOrEmpty(nodeValue)) return;

            foreach (TreeNodeCustom node in plTreeView.Controls.OfType<TreeNodeCustom>())
            {
                string menuKey = node.Tag + "";
                if (menuKey.Length <= nodeValue.Length || !menuKey.StartsWith(nodeValue)) continue;
                SetNodeVisibleState(node, true);
            }
            RefreshNodeStyles();
            ReflowTreeNodes();
        }

        /// <summary>
        /// 选中指定节点，仅更新样式，不触发业务回调。
        /// </summary>
        public void SelectNode(string nodeValue)
        {
            if (string.IsNullOrEmpty(nodeValue)) return;

            TreeNodeCustom treeNode = plTreeView.Controls.OfType<TreeNodeCustom>().FirstOrDefault(n => (n.Tag + "").Equals(nodeValue));
            if (treeNode == null) return;

            SelectNodeButton(treeNode.btnTreeNode, nodeValue);
        }

        private int GetNodeLevel(string nodeValue)
        {
            if (ParentKeyLength <= 0 || string.IsNullOrEmpty(nodeValue)) return 1;
            return Math.Max(1, nodeValue.Length / ParentKeyLength);
        }

        private int GetVisualNodeLevel(string nodeValue)
        {
            return GetNodeLevel(nodeValue);
        }

        private bool IsDefaultExpandedChildNode(string nodeValue)
        {
            return !string.IsNullOrEmpty(_defaultExpandNodeValue)
                && nodeValue.Length > _defaultExpandNodeValue.Length
                && nodeValue.StartsWith(_defaultExpandNodeValue);
        }

        private void SetNodeVisibleState(TreeNodeCustom node, bool visible)
        {
            if (node == null) return;

            string nodeValue = node.Tag + "";
            if (visible)
            {
                _visibleNodeValues.Add(nodeValue);
            }
            else
            {
                _visibleNodeValues.Remove(nodeValue);
            }
            node.Visible = visible;
        }

        private bool GetNodeVisibleState(TreeNodeCustom node)
        {
            if (node == null) return false;

            return _visibleNodeValues.Contains(node.Tag + "");
        }

        private void RefreshNodeStyles()
        {
            foreach (TreeNodeCustom node in plTreeView.Controls.OfType<TreeNodeCustom>())
            {
                string nodeValue = node.Tag + "";
                SetNodeDefaultStyle(node.btnTreeNode, GetVisualNodeLevel(nodeValue));
            }

            if (!string.IsNullOrEmpty(_lastMenuId) && _dicButtons.ContainsKey(_lastMenuId))
            {
                Button button = _dicButtons[_lastMenuId];
                TreeNodeCustom treeNode = button.Parent as TreeNodeCustom;
                SetNodeSelectImage(button, GetVisualNodeLevel(treeNode == null ? string.Empty : treeNode.Tag + ""));
            }
        }

        private void ReflowTreeNodes()
        {
            if (plTreeView == null) return;

            int top = 0;
            int width = Math.Max(0, plTreeView.ClientSize.Width);
            var parNodes = plTreeView.Controls.OfType<TreeNodeCustom>().OrderBy(n => n.TabIndex);
            foreach (TreeNodeCustom node in parNodes)
            {
                node.Width = width;
                node.Left = 0;
                node.Top = top;
                if (!GetNodeVisibleState(node)) continue;

                top += node.Height;
            }
            plTreeView.AutoScrollMinSize = new Size(0, top);
        }

        private bool HasChildNodes(string nodeValue)
        {
            if (string.IsNullOrEmpty(nodeValue) || !_dicTreeNodes.ContainsKey(nodeValue)) return false;
            return _dicTreeNodes[nodeValue].Any(n => (n.Tag + "").Length > nodeValue.Length);
        }

        private bool HasVisibleChildNodes(string nodeValue)
        {
            if (string.IsNullOrEmpty(nodeValue) || !_dicTreeNodes.ContainsKey(nodeValue)) return false;
            return _dicTreeNodes[nodeValue].Any(n => (n.Tag + "").Length > nodeValue.Length && GetNodeVisibleState(n));
        }

        private Image GetGroupTreeDefaultImage(int nodeLevel)
        {
            if (nodeLevel <= 1) return Lskj.Main.Properties.Resources.tree_group_l1_default;
            if (nodeLevel == 2) return Lskj.Main.Properties.Resources.tree_group_l2_default;
            return Lskj.Main.Properties.Resources.tree_group_l3_default;
        }

        private Image GetGroupTreeMoveImage(int nodeLevel)
        {
            if (nodeLevel <= 1) return Lskj.Main.Properties.Resources.tree_group_l1_move;
            if (nodeLevel == 2) return Lskj.Main.Properties.Resources.tree_group_l2_move;
            return Lskj.Main.Properties.Resources.tree_group_l3_move;
        }

        private Image GetGroupTreeSelectImage(int nodeLevel)
        {
            if (nodeLevel <= 1) return Lskj.Main.Properties.Resources.tree_group_l1_select;
            if (nodeLevel == 2) return Lskj.Main.Properties.Resources.tree_group_l2_select;
            return Lskj.Main.Properties.Resources.tree_group_l3_select;
        }

        private void SetNodeDefaultStyle(Button button, int nodeLevel)
        {
            if (button == null) return;

            if (UseGroupTreeImageStyle)
            {
                button.BackgroundImage = GetGroupTreeDefaultImage(nodeLevel);
                button.BackgroundImageLayout = ImageLayout.Stretch;
                button.Image = null;
                button.TextImageRelation = TextImageRelation.Overlay;
                button.TabStop = false;
                button.FlatAppearance.BorderSize = 0;
                button.FlatAppearance.MouseDownBackColor = Color.Transparent;
                button.FlatAppearance.MouseOverBackColor = Color.Transparent;
                button.Padding = new Padding(34 + Math.Max(0, nodeLevel - 1) * 12, 0, 3, 0);
                button.Font = new Font("微软雅黑", 12);
                button.TextAlign = ContentAlignment.MiddleLeft;
                return;
            }

            if (UseMenuBarTextStyle)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.left_default;
                button.BackgroundImageLayout = ImageLayout.Stretch;
                button.Image = null;
                button.TextImageRelation = TextImageRelation.Overlay;
                button.Font = new Font("微软雅黑", 10);
                button.Padding = new Padding(20 + Math.Max(0, nodeLevel - 1) * 20, 3, 3, 3);
                button.TextAlign = ContentAlignment.MiddleLeft;
                return;
            }

            if (nodeLevel <= 1)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node_default;
                button.Image = null;
                button.Padding = new Padding(10, 0, 0, 0);
                button.Font = new Font("微软雅黑", 12);
            }
            else if (nodeLevel == 2)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node2_default;
                button.Image = null;
                button.Padding = new Padding(20, 1, 3, 3);
                button.Font = new Font("微软雅黑", 11);
            }
            else
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node3_default;
                button.Image = null;
                button.Padding = new Padding(30 + Math.Max(0, nodeLevel - 3) * 10, 1, 3, 3);
                button.Font = new Font("微软雅黑", 10);
            }
        }

        private void SetNodeDefaultImage(Button button, int nodeLevel)
        {
            if (button == null) return;

            if (UseGroupTreeImageStyle)
            {
                button.BackgroundImage = GetGroupTreeDefaultImage(nodeLevel);
                return;
            }

            if (UseMenuBarTextStyle)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.left_default;
                return;
            }

            if (nodeLevel <= 1)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node_default;
            }
            else if (nodeLevel == 2)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node2_default;
            }
            else
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node3_default;
            }
        }

        private void SetNodeSelectImage(Button button, int nodeLevel)
        {
            if (button == null) return;

            if (UseGroupTreeImageStyle)
            {
                button.BackgroundImage = GetGroupTreeSelectImage(nodeLevel);
                return;
            }

            if (UseMenuBarTextStyle)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.left_select;
                return;
            }

            if (nodeLevel <= 1)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node_select;
            }
            else if (nodeLevel == 2)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node2_select;
            }
            else
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node3_select;
            }
        }

        private void SetNodeMoveImage(Button button, int nodeLevel)
        {
            if (button == null) return;

            if (UseGroupTreeImageStyle)
            {
                button.BackgroundImage = GetGroupTreeMoveImage(nodeLevel);
                return;
            }

            if (UseMenuBarTextStyle)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.left_select;
                return;
            }

            if (nodeLevel <= 1)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node_select;
            }
            else if (nodeLevel == 2)
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node2_move;
            }
            else
            {
                button.BackgroundImage = Lskj.Main.Properties.Resources.node3_move;
            }
        }

        private void SelectNodeButton(Button button, string nodeValue)
        {
            if (button == null) return;

            if (!string.IsNullOrEmpty(_lastMenuId) && _lastMenuId != button.Name && _dicButtons.ContainsKey(_lastMenuId))
            {
                Button lastButton = _dicButtons[_lastMenuId];
                TreeNodeCustom lastNode = lastButton.Parent as TreeNodeCustom;
                SetNodeDefaultImage(lastButton, GetVisualNodeLevel(lastNode == null ? string.Empty : lastNode.Tag + ""));
            }

            SetNodeSelectImage(button, GetVisualNodeLevel(nodeValue));
            _lastMenuId = button.Name;
        }

        private void TriggerNodeEvent(Button button, string nodeValue)
        {
            SelectNodeButton(button, nodeValue);
            if (OnButtonClickEvent != null)
            {
                this.OnButtonClickEvent(button);
            }
        }
        /// <summary>
        /// <para>说明：树点击</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        private void btnTreeNode_Click(object sender, EventArgs e)
        {
            try
            {
                SuspendDrawing(plTreeView);
                TreeNodeCustom treeNode = (sender as Button).Parent as TreeNodeCustom;
                if (treeNode != null)
                {
                    string nodeValue = treeNode.Tag + "";
                    if (_lastTreeNode == null)
                    {
                        _lastTreeNode = nodeValue;
                    }
                    int nodeLevel = GetVisualNodeLevel(nodeValue);
                    bool hasChildNodes = HasChildNodes(nodeValue);
                    List<TreeNodeCustom> treeNodes = new List<TreeNodeCustom>();
                    // 展开当前点击节点
                    if (hasChildNodes && AllowNodeCollapse)
                    {
                        treeNodes = _dicTreeNodes[nodeValue];
                        foreach (TreeNodeCustom node in treeNodes)
                        {
                            string menuKey = node.Tag + "";
                            if (menuKey.Length <= nodeValue.Length) continue;
                            SetNodeVisibleState(node, !GetNodeVisibleState(node));
                        }
                        ReflowTreeNodes();
                        if (!RaiseClickEventOnAllNodes)
                        {
                            if (HasVisibleChildNodes(nodeValue))
                            {
                                SetNodeSelectImage(treeNode.btnTreeNode, nodeLevel);
                            }
                            else
                            {
                                SetNodeDefaultImage(treeNode.btnTreeNode, nodeLevel);
                            }
                        }
                    }
                    // 点击根节点隐藏所有子节点
                    if (AllowNodeCollapse && nodeValue.Length == ParentKeyLength && !HasVisibleChildNodes(nodeValue))
                    {
                        treeNodes = getChildNodes(nodeValue);
                        foreach (TreeNodeCustom node in treeNodes)
                        {
                            SetNodeVisibleState(node, false);
                            //Application.DoEvents();// 处理当前消息队列中的所有windows消息
                        }
                        ReflowTreeNodes();
                    }
                    // 点击末节点
                    if (RaiseClickEventOnAllNodes || nodeValue.Length == ParentKeyLength * 3)
                    {
                        TriggerNodeEvent(treeNode.btnTreeNode, nodeValue);
                    }
                    _lastTreeNode = nodeValue;
                }
            }
            catch (Exception)
            {
            }
            ResumeDrawing(plTreeView);
        }
        /// <summary>
        /// <para>说明：鼠标移动</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        private void btnTreeNode_MouseMove(object sender, MouseEventArgs e)
        {
            try
            {
                Button button = sender as Button;
                if (button != null)
                {
                    this.Cursor = Cursors.Hand;

                    TreeNodeCustom treeNode = button.Parent as TreeNodeCustom;
                    string treeNodeTag = treeNode.Tag + "";
                    int nodeLevel = GetVisualNodeLevel(treeNodeTag);
                    if (SwitchOnMouseMove && button.Name != _lastMenuId)
                    {
                        TriggerNodeEvent(button, treeNodeTag);
                        if (!UseGroupTreeImageStyle)
                        {
                            SetNodeMoveImage(button, nodeLevel);
                        }
                        return;
                    }

                    if (button.Name == _lastMenuId)
                    {
                        return;
                    }

                    if (UseGroupTreeImageStyle)
                    {
                        SetNodeMoveImage(button, nodeLevel);
                        return;
                    }

                    if (nodeLevel == 2)
                    {
                        // 第一级节点
                        if (HasChildNodes(treeNodeTag))
                        {
                            button.BackgroundImage = HasVisibleChildNodes(treeNodeTag) ? Lskj.Main.Properties.Resources.node2_select : Lskj.Main.Properties.Resources.node2_move;
                        }
                        else
                        {
                            button.BackgroundImage = Lskj.Main.Properties.Resources.node2_move;
                        }
                    }
                    else
                    {
                        // 末节点
                        SetNodeMoveImage(button, nodeLevel);
                    }

                }
            }
            catch (Exception ex)
            {
            }
        }
        /// <summary>
        /// <para>说明：鼠标离开</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        private void btnTreeNode_MouseLeave(object sender, EventArgs e)
        {
            try
            {
                Button button = sender as Button;
                if (button != null)
                {
                    this.Cursor = Cursors.Hand;

                    TreeNodeCustom treeNode = button.Parent as TreeNodeCustom;
                    string treeNodeTag = treeNode.Tag + "";
                    int nodeLevel = GetVisualNodeLevel(treeNodeTag);
                    if (button.Name == _lastMenuId)
                    {
                        return;
                    }

                    if (UseGroupTreeImageStyle)
                    {
                        SetNodeDefaultImage(button, nodeLevel);
                        return;
                    }

                    if (nodeLevel == 2)
                    {
                        // 第一级节点
                        if (HasChildNodes(treeNodeTag))
                        {
                            button.BackgroundImage = HasVisibleChildNodes(treeNodeTag) ? Lskj.Main.Properties.Resources.node2_select : Lskj.Main.Properties.Resources.node2_default;
                        }
                        else
                        {
                            button.BackgroundImage = Lskj.Main.Properties.Resources.node2_default;
                        }
                    }
                    else
                    {
                        // 末节点
                        SetNodeDefaultImage(button, nodeLevel);
                    }

                }
            }
            catch (Exception ex)
            {
            }
        }
        /// <summary>
        /// <para>说明：获取子节点</para>
        /// <para>创建人 龚宇超</para>
        /// <para>创建日期：2018-04-24 </para>
        /// <para>修改人：</para>
        /// <para>修改日期：</para>
        /// <para>修改备注：</para>
        /// <para>版本：1.0</para>
        /// </summary>
        /// <returns></returns>
        private List<TreeNodeCustom> getChildNodes(string nodeValue)
        {
            List<TreeNodeCustom> treeNodes = new List<TreeNodeCustom>();

            // 获取第3个节点之后的节点
            DataRow[] rowChilds = _dataSource.Rows.Cast<DataRow>().Where(x => (x[ParentField] + "").Length == nodeValue.Length * 2 && (x[ParentField] + "").Substring(0, nodeValue.Length) == nodeValue).ToArray();

            foreach (DataRow item in rowChilds)
            {
                if (_dicTreeNodes.ContainsKey(item[ParentField] + ""))
                {
                    List<TreeNodeCustom> nodeChilds = _dicTreeNodes[item[ParentField] + ""];
                    foreach (TreeNodeCustom node in nodeChilds)
                    {
                        treeNodes.Add(node);
                    }
                }
            }
            return treeNodes;
        }
    }

}