ASP.NET DEMO 18: 如何编程动态创建 Menu

ASP.NET DEMO 15: 如何编程动态创建 TreeView 的姊妹篇：

<% @ Page Language = " C# "   %>
<% @ Import Namespace = " System.Data "   %>
<% @ Import Namespace = " System.Data.OleDb "   %>

<! DOCTYPE html PUBLIC  " -//W3C//DTD XHTML 1.0 Transitional//EN "   " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd " >

< script runat = " server " >
     protected   void  Page_Load( object  sender, EventArgs e)
    {
         if  ( ! IsPostBack) {
            CreateMenu();
        }
    }

     ///   <summary>
     ///  创建 Menu
     ///  此方法采取一次性加载目标数据到 DataTable，递归查询 DataTable ，创建子节点
     ///   </summary>
     private   void  CreateMenu()
    {
         //
         const   int  VirtualRootId  =   0 ;  //  虚拟的根节点 ID， 表中 ParentID=0 的节点表示无实际父节点
         const   string  SQL_SELECT  =   " SELECT NodeId, NodeName,ParentId FROM TreeView ORDER BY NodeId ASC " ;
        
         //
         string  connStr  =   " Provider=Microsoft.Jet.OleDb.4.0;data source= "   +  Server.MapPath( " Menu_CreateMenuDynamicFromDb.mdb " ); ;        
         //
        OleDbDataAdapter da  =   new  OleDbDataAdapter(SQL_SELECT, connStr);
        DataTable dt  =   new  DataTable();
         //
        da.Fill(dt);
         //
        CreateMenuRecursive(mnuDemo.Items, dt, VirtualRootId);
    }

     ///   <summary>
     ///  递归查询数据，创建 MenuItem 节点
     ///   </summary>
     ///   <param name="items"></param>
     ///   <param name="dataSource"></param>
     ///   <param name="parentId"></param>
     private   void  CreateMenuRecursive(MenuItemCollection items, DataTable dataSource,  int  parentId)
    {
         //
         string  fliter  =  String.Format( " ParentId={0} " , parentId);
         //  查询子节点
        DataRow[] drArr  =  dataSource.Select(fliter);
        
        MenuItem item;        
         foreach (DataRow dr  in  drArr) {                        
             //
            item  =   new  MenuItem();
            items.Add(item);
            item.Text  =  ( string )dr[ " NodeName " ];            
             //  设置其他属性
             //       
                       
             //  递归创建子节点
            CreateMenuRecursive(item.ChildItems, dataSource, ( int )dr[ " NodeId " ]);
            
             //  移除已添加行，提高性能
            dataSource.Rows.Remove(dr);
        }
    }

</ script >

< html xmlns = " http://www.w3.org/1999/xhtml "   >
< head id = " Head1 "  runat = " server " >
     < title > CreateMenuResursiveFromDb </ title >
</ head >
< body >
     < form id = " form1 "  runat = " server " >
     < div >
    < h1 > 动态创建Menu </ h1 >
         < asp:Menu ID = " mnuDemo "  runat = " server "  ExpandDepth = " 1 "  BackColor = " #FFFBD6 "  
            DynamicHorizontalOffset = " 2 "  Font - Names = " Verdana "  Font - Size = " 0.8em "  
            ForeColor = " #990000 "  StaticSubMenuIndent = " 10px " >
             < StaticSelectedStyle BackColor = " #FFCC66 "   />
             < StaticMenuItemStyle HorizontalPadding = " 5px "  VerticalPadding = " 2px "   />
             < DynamicHoverStyle BackColor = " #990000 "  ForeColor = " White "   />
             < DynamicMenuStyle BackColor = " #FFFBD6 "   />
             < DynamicSelectedStyle BackColor = " #FFCC66 "   />
             < DynamicMenuItemStyle HorizontalPadding = " 5px "  VerticalPadding = " 2px "   />
             < StaticHoverStyle BackColor = " #990000 "  ForeColor = " White "   />
         </ asp:Menu >
     </ div >
     </ form >
</ body >
</ html >

 

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