winform树形菜单无限级分类实例

/// <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();
         }