/// <summary>          /// 创建树形菜单          /// </summary>          public void AddTree(int ParentID, TreeNode pNode)          {              // 数据库名字字段              string strName = "Name";              // 数据库ID字段              string strID = "ID";              // 数据库父级ID字段              string strParentID = "ParentID";              DataTable dt = typeManager.GetAllList();              DataView dvTree = new DataView(dt);              dvTree.RowFilter = strParentID + " = " + ParentID;              foreach (DataRowView Row in dvTree)              {                  TreeNode Node = new TreeNode();                  if (pNode == null)                  {                      Node.Text = Row[strName].ToString();                      Node.Name = Row[strName].ToString();                      Node.Tag = Row[strID].ToString();                      Node.ImageIndex = 1;                      this.treeView1.Nodes.Add(Node);                      AddTree(Int32.Parse(Row[strID].ToString()), Node); //再次递归                  }                  else                  {                       Node.Text = Row[strName].ToString();                      Node.Name = Row[strName].ToString();                      Node.Tag = Row[strID].ToString();                      Node.ImageIndex = 1;                      pNode.Nodes.Add(Node);                      AddTree(Int32.Parse(Row[strID].ToString()), Node); //再次递归                  }              }          }          /// <summary>          /// 主窗体加载          /// </summary>          /// <param name="sender"></param>          /// <param name="e"></param>          private void frmTree_Load(object sender, EventArgs e)          {              // 根节点ID值              int i = 0;              this.treeView1.Nodes.Clear();              AddTree(i, (TreeNode)null);              treeView1.HideSelection = true;              treeView1.ShowLines = true;          }

private void treeView1_NodeMouseDoubleClick(object sender, TreeNodeMouseClickEventArgs e)          {              ImageChange(e);          }          private void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)          {              ImageChange(e);          }          /// <summary>          /// 变换文件夹图标          /// </summary>          /// <param name="e"></param>          public void ImageChange(TreeNodeMouseClickEventArgs e)          {              if (null == e.Node.FirstNode)              {                  e.Node.ImageIndex = 0;                  e.Node.SelectedImageIndex = 0;              }              else              {                  if (e.Node.IsExpanded)                  {                      e.Node.ImageIndex = 0;                      e.Node.SelectedImageIndex = 0;                  }                  else                  {                      e.Node.ImageIndex = 1;                      e.Node.SelectedImageIndex = 1;                  }              }          }

delegate void Mydelegate(string name, string id);          Mydelegate md = null;          public frmTree()          {              InitializeComponent();          }          /// <summary>          /// 打开新窗口          /// </summary>          /// <param name="sender"></param>          /// <param name="e"></param>          private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)          {              // 设置显示图标的变换              if(null== e.Node.FirstNode)              {                  e.Node.ImageIndex = 1;                  e.Node.SelectedImageIndex = 0;              }              // 打开新的窗口，每一级对应一类窗口              if (e.Node != null && null == e.Node.FirstNode)              {                  string tag =e.Node.Tag.ToString();                  string name = e.Node.Text.ToString();                  switch(e.Node.Level)                  {                      case 0:                          this.md= new Mydelegate(OpenForm1);                          break;                      case 1:                          this.md = new Mydelegate(OpenForm2);                          break;                      case 2:                          this.md = new Mydelegate(OpenForm3);                          break;                  }                  md(name, tag);              }          }          /// <summary>          /// 打开新窗口          /// </summary>          /// <param name="name">传递参数</param>          /// <param name="id">传递参数</param>          public static void OpenForm1(string name,string id)          {              Form newForm = new Form1();              newForm.ShowDialog();          }          public static void OpenForm2(string name, string id)          {              Form newForm = new Form2();              newForm.ShowDialog();          }          public static void OpenForm3(string name, string id)          {              Form newForm = new Form3();              newForm.ShowDialog();          }