ShowRepeater模拟简单的Repeater

为了更好的理解常用的Repeater等数据控件，自己就试着写一下，这里只当笔记！

ViewRepeater.ascx里没什么好说的，只有一个占位符

<% @ Control Language = " C# "  AutoEventWireup = " true "  CodeBehind = " ViewRepeater.ascx.cs "  Inherits = " ShowRepeater.TLC "   %>
< asp:PlaceHolder  ID ="PlaceHolder1"  runat ="server" ></ asp:PlaceHolder >

 

cs文件时多了一点

 

代码

public   partial   class  ShowRepeater : UserControl, INamingContainer
    {
         private  ITemplate _itemTemplate  =   null ;
         private  ITemplate _headerTemplate  =   null ;
         private  ITemplate _footerTemplate  =   null ;
         private   object  _dataSource  =   null ;

         public   object  DataSource
        {
             get  {  return  _dataSource; }
             set  {
                 if  (value  is  IEnumerable)
                    _dataSource  =  value;
                 else   if  (value  is  IListSource)
                    _dataSource  =  ((IListSource)value).GetList();
                 else
                     throw   new  ArgumentException( " DataSource应该是IEnumerable. " );
            }
        }
        [TemplateContainer( typeof (ItemContainer))]
        [PersistenceMode(PersistenceMode.InnerDefaultProperty)]
         public  ITemplate ItemTemplate
        {
             get
            {
                 return  _itemTemplate;
            }
             set
            {
                _itemTemplate  =  value;
            }
        }
        [TemplateContainer( typeof (HeaderContainer))]
        [PersistenceMode(PersistenceMode.InnerProperty)]
         public  ITemplate HeaderTemplate {
             get  {  return  _headerTemplate; }
             set  { _headerTemplate  =  value; }
        }
        [TemplateContainer( typeof (HeaderContainer))]
        [PersistenceMode(PersistenceMode.InnerProperty)]
         public  ITemplate FooterTemplate
        {
             get  {  return  _footerTemplate; }
             set  { _footerTemplate  =  value; }
        }

         public   override   void  DataBind()
        {
             if  (_headerTemplate  !=   null )
            {
                HeaderContainer hcon  =   new  HeaderContainer();
                _headerTemplate.InstantiateIn(hcon);
                PlaceHolder1.Controls.Add(hcon);
            }

             if  (_itemTemplate  !=   null   &&  _dataSource  !=   null )
            {
                 int  i  =   0 ;
                IEnumerable enu  =  (IEnumerable)_dataSource;
                 foreach  ( object  o  in  enu)
                {
                    ItemContainer con  =   new  ItemContainer(i, o);
                    _itemTemplate.InstantiateIn(con);
                    PlaceHolder1.Controls.Add(con);
                    i ++ ;
                }
            }

             if  (_footerTemplate  !=   null )
            {
                FooterContainer fcon  =   new  FooterContainer();
                _footerTemplate.InstantiateIn(fcon);
                PlaceHolder1.Controls.Add(fcon);
            }
             base .DataBind();
        }

         public   class  ItemContainer : Control, INamingContainer, IDataItemContainer
        {
             private   int  _itemIndex;
             private   object  _dataItem;
             internal  ItemContainer( int  itemIndex, object  dataItem)
            {
                _itemIndex  =  itemIndex;
                _dataItem  =  dataItem;
            }
             public   int  Index {  get  {  return  _itemIndex; } }

             #region  IDataItemContainer 成员

             public   object  DataItem
            {
                 get  {
                     return  _dataItem;
                }
            }

             public   int  DataItemIndex
            {
                 get  {  return  _itemIndex; }
            }

             public   int  DisplayIndex
            {
                 get  {  return  _itemIndex; }
            }

             #endregion
        }

         public   class  HeaderContainer : Control, INamingContainer { }
         public   class  FooterContainer : Control, INamingContainer { }

    }

 

用一个页面一测试，哈哈居然可以啦！欣慰！

前端主要代码：

代码

<% @ Register TagPrefix = " uc "  TagName = " vp "  Src = " ~/ViewRepeater.ascx "   %>

< uc:vp  runat ="server"  ID ="vp" >
         < HeaderTemplate >
             < table  width ="500" >
                 < tr >
                     < th >
                        ID
                     </ th >
                     < th >
                        TItle
                     </ th >
                     < th >
                        DESC
                     </ th >
                 </ tr >
         </ HeaderTemplate >
         < ItemTemplate >
             < tr >
                 < td >
                     <% #  Eval ( " ID " )  %>
                 </ td >
                 < td >
                     <% #  Eval ( " Title " )  %>
                 </ td >
                 < td >
                     <% #  Eval ( " Desc " )  %>
                 </ td >
             </ tr >
         </ ItemTemplate >
         < FooterTemplate >
             </ table >
         </ FooterTemplate >
     </ uc:vp >

 

后端：

 

代码

protected   void  Page_Load( object  sender, EventArgs e)
        {
             if  ( ! IsPostBack)
            {
                vp.DataSource  =  gettable();
                vp.DataBind();
            }
        }
        DataTable gettable()
        {
            DataTable dt  =   new  DataTable();
            dt.Columns.Add( new  DataColumn( " ID " ,  typeof ( int )));
            dt.Columns.Add( new  DataColumn( " Title " ,  typeof ( string )));
            dt.Columns.Add( new  DataColumn ( " Desc " , typeof  ( string )));
             for  ( int  i  =   0 ; i  <   5 ; i ++ )
            {
                DataRow dr  =  dt.NewRow();
                dr[ 0 ]  =  i  +   1 ;
                dr[ 1 ]  =   " Title "   +  (i  +   1 );
                dr[ 2 ]  =   " Desc "   +  (i  +   1 );
                dt.Rows.Add(dr);
            }
             return  dt;
        }

 

效果如图：

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现在还是懵懵懂懂，继续学习中....