Minifycode 2022-05-12 Viewed 1.5K times ASP.NET

In this article, you will learn what is difference Between List and IList in C# .Net

In this article, you will learn, difference between List and IList in C# .Net is that List is a class that represents a list of objects which can be 
accessed by index while IList is an interface that represents a collection of objects which can be accessed by index.

IList<T> is an interface implemented by List<T>.

You cannot create a concrete instance of an interface:

//this will not compile
IList<Employee> EmpList = new IList<Employee>();    

//this is what you're really looking for:
List<Employee> EmpList = new List<Employee>();

//but this will also compile:
IList<Employee> EmpList = new List<Employee>();


Number of helper methods

List<T> has more helper methods than IList<T>. So, this is another difference between List and IList in C# .Net.

IList is an interface, List is a class that implements it, the List type explicitly implements the non generic IList interface.

The main difference between List and IList in C# .Net is that List is a class that represents a list of objects which can be  accessed by index while IList is an interface that represents a collection of objects which can be accessed by index.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html> <html> <head> <title>Asp.Net Repeater Control</title> </head> <body> <form id="form1" runat="server"> <div style="font:13px Verdana;width:310px;"> <asp:ScriptManager ID="scriptManager" runat="server" EnablePageMethods="true" /> <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"> <ContentTemplate> <h3>Asp.Net Repeater Control</h3> <%--THE REPEATER CONTROL.--%> <asp:Repeater id="rp" runat="server"> <%--HEADER OF THE REPEATER--%> <HeaderTemplate> <table border="0" width="200px"> </HeaderTemplate> <%--SHOWING ITEMS--%> <ItemTemplate> <tr> <td style="padding:2px; border:solid 1px #CCC;"> <asp:Label Text='<%# Container.DataItem.ToString() %>' runat="server"></asp:Label> </td> </tr> </ItemTemplate> <%--ALTERNATE TEMPLATE (SHOWING ITEMS IN DIFFERENT COLOR--%> <AlternatingItemTemplate> <tr> <td style="padding:2px; border:solid 1px #CCC; background:#EAF7FB; width:200px;"> <asp:Label Text='<%# Container.DataItem.ToString() %>' runat="server"></asp:Label> </td> </tr> </AlternatingItemTemplate> <%--REPEATER FOOTER--%> <FooterTemplate> </table> <div style="padding:20px 0;"> <asp:Label ID="lblFoot" runat="server"></asp:Label> </div> </FooterTemplate> </asp:Repeater> <%--BUTTON CONTROL--%> <asp:Button ID="btVF" Text="View Files" AutoPostBack="true" OnClick="Show" Font-Names="sanserif" Font-Italic="true" Font-Size="155%" runat="server" /> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="PostBackTrigger" /> </Triggers> </asp:UpdatePanel> </div> </form> </body> </html> using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.IO; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) {} protected void Show(object sender, EventArgs e) { DirectoryInfo Folder = new DirectoryInfo(Server.MapPath("Files\\")); FileInfo[] fileList = Folder.GetFiles("*.*"); //BIND THE FILE LIST WITH THE REPEATER CONTROL. rp.DataSource = fileList; rp.DataBind(); } } Adding the <AlternatingTemplate> below the <ItemTemplate> will show files with a different background color for every alternate row. <AlternatingItemTemplate> <div style="padding:3px; border:solid 1px #FFF; background:#black"> <asp:Label Text='<%# Container.DataItem.ToString() %>' runat="server"></asp:Label> </div> </AlternatingItemTemplate> </AlternatingItemTemplate> <SeparatorTemplate><hr /> </SeparatorTemplate> Add the <HeaderTemplate> element just above the <ItemTemplate> <HeaderTemplate> <div style="padding-bottom:20px"><strong>Files</strong> (Header)</div> </HeaderTemplate> Repeater with <FooterTemplate> element <FooterTemplate> <div style="padding-top:20px"><asp:Label ID="lblFooter" runat="server"></asp:Label></div> </FooterTemplate> Code Behind In C# Control ft = rp.Controls[rep.Controls.Count - 1].Controls[0]; Label lbl_Footer = ft.FindControl("lblFooter") as Label; lbl_Footer.Text = "Showing total <b>" + fileList.Length + "</b> files in the Footer.";