Asp.net adds a group of controls through repeater Loop

Asp.net uses the repeater loop to add a corresponding set of controls. It is mainly used for dynamic and repeated post data from the background to the foreground.CodeAnd can add any number of duplicate modules in the background. This method is often used in actual projects. This article briefly introduces the repeater structure and usage.

For example, if we want to implement the following style, of course, the data is obtained from the background, and the number of data rows is variable.

First, define the data structure: (the defined data structure should include the structure shown at the front end as much as possible)

     Public   Class  Evaluation {  Private   String  Productid;  Private   String  Rating;  Public Evaluation (String Productid, String  Rating ){  This . Productid = Productid;  This . Rating = Rating ;}  Public   String  Productid {  Get  {  Return Productid ;}}  Public   String  Rating {  Get  {  Return  Rating ;}}} 

 

Background processing method:

     Public   Partial   Class  Testrepeatorcontrol: system. Web. UI. Page {  Protected  Void Page_load ( Object  Sender, eventargs e ){  If (! Ispostback) {arraylist values = New  Arraylist (); values. Add (  New Evaluation ( "  Razor wiper blades  " , "  Good "  ); Values. Add (  New Evaluation ( "  Shoe-so-soft softening Polish  " , "  Poor  "  ); Values. Add (  New Evaluation ( "  Dynasmile dental fixative  " , " Fair  "  ); Repeater1.datasource = Values; repeater1.databind ();}}  Protected   Void Repeaterincluitemdatabound ( Object  Sender, repeateritemeventargs e ){  //  This event is raised for the header, the footer, separators, and items.  // Execute the following logic for items and alternating items.              If (E. Item. itemtype = listitemtype. Item | E. Item. itemtype = Listitemtype. alternatingitem ){  If (Evaluation) E. Item. dataitem). rating = "  Good  "  ) {(Label) E. Item. findcontrol (  "  Ratinglabel  " ). Text = " <B> *** good *** </B>  "  ;}}}} 

Here we can see that the repeater data source requires an object instance that implements the ienumerable interface, for example, the arraylist object instance is used here.

The repeaterincluitemdatabound method can be used to specially process cyclic items.

 

Finally, let's look at the front-end code implementation:

 <%  @ Page Language  =  "  C #  " Autoeventwireup  =  "  True  "  Codebehind  =  "  Testrepeatorcontrol. aspx. CS  "  Inherits =  "  Ericsunwebappproject. testrepeatorcontrol  "   %>  <!  Doctype html  >  <  Html  Xmlns  = "Http://www.w3.org/1999/xhtml"  >  < Head  Runat  = "Server"  >      <  Title  > </  Title  >  </  Head  >  <  Body  >      <  Form ID  = "Form1"  Runat  = "Server"  >          <  Div  >              <  ASP: Repeater  ID  = "Repeater1"  Runat  = "Server"  Onitemdatabound  = "Repeaterincluitemdatabound" >                                  <  Headertemplate  >                      <  Table  Border  = "1"  >                          <  Tr  >                              <  TD  > <  B  > Product</  B  > </  TD  >                              <  TD  > <  B  > Consumer rating </  B  > </  TD  >                          </  Tr >                  </  Headertemplate  >                  <  Itemtemplate  >                          <  Tr  >                              <  TD  >   <  ASP: Label  ID  = "Label1" Text  = '<% #  Databinder. eval (container. dataitem, "productid") %  > 'Runat = "server"/> </  TD  >                              <  TD  >   <  ASP: Label  ID  = "Ratinglabel"  Text  = '<% # Databinder. eval (container. dataitem, "rating") %  > 'Runat = "server"/> </  TD  >                          </  Tr  >                  </  Itemtemplate  >                  <  Footertemplate  >                      </  Table >                  </  Footertemplate  >              </  ASP: Repeater  >          </  Div  >      </  Form  >  </  Body  >  </ Html  > 

Here we can clearly see that the repeater has three structures: headertemplate, itemtemplate, and footertemplate.

When the data source is traversed and displayed, the duplicate part is only the part contained in the itemtemplate. Only one portion of headertemplate and footertemplate is displayed. In this way, we can handle the situation of "beginning and end are special and the content is duplicated.

Here, we cyclically process Tr and TD. If we want to cyclically process custom controls or more complex controls (such as Treeview ), you can place the control that we need to repeat in itemtemplate to replace Tr and TD here.

 

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