ADD-EDIT-DELETE FUNCTIONALITY USING DELETGATE AND LINQ.

Create a database name Office with Four Column

1.OfficeId(Auto Increment-Int)
2.OfficeName(nvarhcar(50))
3.City(nvarchar(50))
4.Country(nvarchar(50))

-> Create a .aspx Page name Office.aspx.
-> Create a UserControl OfficeAddEdit.ascx Page.
-> Create a UserControl OfficeList.ascx Page.
-> Add Images Folder and add Edit.gif Image.

Office.aspx Page

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Office.aspx.cs" Inherits="OfficeDelegate.Office" %>
<%@ Register Src="~/OfficeList.ascx" TagName="OfficeList" TagPrefix="uc1" %>
<%@ Register Src="~/OfficeAddEdit.ascx" TagName="OfficeAddEdit" TagPrefix="uc2" %>

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

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
   <title></title>
</head>
<body>
   <form id="form1" runat="server">

   <div>
   <table width="100%" border="0" cellspacing="0" cellpadding="0" class="RightTable">
   <tr>
   <td colspan="2" class="TableHeader">
   <asp:Label ID="lblAvatarappearanceMasterHeader" runat="server" Text=""></asp:Label>
   </td>
   </tr>
   <tr>
   <td>

   <uc1:OfficeList ID="OfficeList1" runat="server" />
   <uc2:OfficeAddEdit ID="OfficeAddEdit1" runat="server" />
   </td>
   </tr>
   </table>
   </div>

   </form>
</body>
</html>

Office.aspx.cs Page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace OfficeDelegate
{
   public delegate void OfficeEditHandler(object sender, OfficeDelegate.OfficeList.OfficeMasterInfo args);
   public delegate void OfficeAddHandler();
   public delegate void OfficeHandler();
   public partial class Office : System.Web.UI.Page
   {
   public int TabID
   {
   get
   {
   if (ViewState["TabId"] == null)
   return 0;
   else
   return Convert.ToInt32(ViewState["TabId"]);
   }

   set
   {
   ViewState["TabId"] = value;
   }
   }


   protected void Page_Load(object sender, EventArgs e)
   {
   OfficeList1.EditEvent += new OfficeEditHandler(List_eventhandler);
   OfficeList1.AddEvent += new OfficeAddHandler(ShowDetails_eventhandler);
   OfficeAddEdit1.eventhandler += new OfficeHandler(Detail_eventhandler);
   if (!IsPostBack)
   {
   TabID = 1;
   ShowHideControl();

   }

   }
   void ShowDetails_eventhandler()
   {

   OfficeAddEdit1.OfficeId = 0;
   TabID = 2;
   ShowHideControl();
   }
   void Detail_eventhandler()
   {
   TabID = 1;
   ShowHideControl();
   }
   void List_eventhandler(object sendar, OfficeDelegate.OfficeList.OfficeMasterInfo asgs)
   {
   OfficeAddEdit1.OfficeId = asgs.iOfficeId;
   TabID = 2;
   ShowHideControl();
   }
   private void ShowHideControl()
   {
   if (TabID == 1)
   {
   OfficeList1.Visible = true;
   OfficeList1.View();
   OfficeAddEdit1.Visible = false;
   }
   else if (TabID == 2)
   {
   OfficeAddEdit1.Visible = true;
   OfficeAddEdit1.View();
   OfficeList1.Visible = false;
   }
   }
   }
}

Now OfficeList.ascx Page

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="OfficeList.ascx.cs" Inherits="OfficeDelegate.OfficeList" %>
<asp:Label ID="lblList" runat="server" Text="List Page"></asp:Label>

  <asp:GridView ID="gvList" runat="server" AutoGenerateColumns="false"
   Width="100%" DataKeyNames="OfficeId" onrowcommand="gvList_RowCommand"
   onrowediting="gvList_RowEditing" >
  <Columns>
   <asp:TemplateField ItemStyle-Width="10px">
   <HeaderTemplate>
   Select
   </HeaderTemplate>
   <ItemTemplate>
   <asp:CheckBox ID="chkSelect" runat="server"/>
   </ItemTemplate>
   <ItemStyle Width="5%" HorizontalAlign="Center" />
   </asp:TemplateField>
   <asp:TemplateField ItemStyle-Width="400px" HeaderText="OfficeName">
   <ItemTemplate>
   <asp:Label ID="lblName" runat="server" Text='<%# Eval("OfficeName") %>'></asp:Label>
   </ItemTemplate>
   </asp:TemplateField>
   <asp:TemplateField ItemStyle-Width="400px" HeaderText="City">
   <ItemTemplate>
   <asp:Label ID="lblCity" runat="server" Text='<%# Eval("City") %>'></asp:Label>
   </ItemTemplate>
   </asp:TemplateField>
   <asp:TemplateField ItemStyle-Width="400px" HeaderText="Country">
   <ItemTemplate>
   <asp:Label ID="lblCountry" runat="server" Text='<%# Eval("Country") %>'></asp:Label>
   </ItemTemplate>
   </asp:TemplateField>
   <asp:TemplateField HeaderText="Action">
   <ItemTemplate>
   <asp:ImageButton ID="btnEdit" runat="server" ImageUrl="~/Images/Edit.gif" CommandName="Edit"
   ToolTip='Edit' CommandArgument='<%# Eval("OfficeId") %>' />
   </ItemTemplate>
   <ItemStyle Width="5%" HorizontalAlign="Center" />
   </asp:TemplateField>
   </Columns>
</asp:GridView>
<br />
<div align="right">
<asp:Button ID="btnAdd" runat="server" Text="Add" onclick="btnAdd_Click" />
<asp:Button ID="btnDelete" runat="server" Text="Delete" onclick="btnDelete_Click" />
</div>

OfficeList.ascx.cs Page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace OfficeDelegate
{
   public partial class OfficeList : System.Web.UI.UserControl
   {
   #region Public Properties
   public event OfficeEditHandler EditEvent;
   public event OfficeAddHandler AddEvent;
   #endregion
   public int TabID
   {
   get
   {
   if (ViewState["TabId"] == null)
   return 0;
   else
   return Convert.ToInt32(ViewState["TabId"]);
   }

   set
   {
   ViewState["TabId"] = value;
   }
   }
   protected void Page_Load(object sender, EventArgs e)
   {

   }
   #region Methods
   private void Bind()
   {
   try
   {
   OfficeDataContext db = new OfficeDataContext();
   var office = from l in db.Offices select l;
   gvList.DataSource = office;
   gvList.DataBind();
   }
   catch (Exception ex)
   {


   }
   }
   #endregion
   public void View()
   {
   Bind();
   }

   protected void btnAdd_Click(object sender, EventArgs e)
   {
   AddEvent();
   }

   protected void btnDelete_Click(object sender, EventArgs e)
   {
   OfficeDataContext db = new OfficeDataContext();
   for (int i = 0; i < gvList.Rows.Count; i++)
   {
   CheckBox chk = (CheckBox)(gvList.Rows[i].FindControl("chkSelect"));
   if (chk.Checked == true)
   {
   var delete = from l in db.Offices where l.OfficeId == Convert.ToInt32(gvList.DataKeys[i].Value) select l;
   db.Offices.DeleteAllOnSubmit(delete);
   db.SubmitChanges();
   }

   }
   Bind();

   }

   protected void gvList_RowCommand(object sender, GridViewCommandEventArgs e)
   {
   try
   {
   if (e.CommandName == "Edit")
   {
   int iID = Convert.ToInt32(e.CommandArgument.ToString());
   OfficeMasterInfo args = new OfficeMasterInfo();
   args.iOfficeId = iID;
   EditEvent(this, args);
   TabID = 2;
   }
   }
   catch (Exception ex)
   {

   }
   }

   protected void gvList_RowEditing(object sender, GridViewEditEventArgs e)
   {

   }
   public class OfficeMasterInfo
   {
   public int iOfficeId;
   }
   }
}

OfficeAddEdit.ascx Page

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="OfficeAddEdit.ascx.cs" Inherits="OfficeDelegate.OfficeAddEdit" %>
<table>
<tr>
<td>
<asp:Label ID="lblName" Text="OfficeName" runat="server"></asp:Label>
</td>
<td>
<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="LblCity" Text="City" runat="server"></asp:Label>
</td>
<td>
<asp:TextBox ID="txtCity" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="lblCountry" Text="Country" runat="server"></asp:Label>
</td>
<td>
<asp:TextBox ID="txtCountry" runat="server"></asp:TextBox>
</td>
</tr>
</table>
<div align="right">
<asp:Button ID="btnAdd" Text="Add" runat="server" onclick="btnAdd_Click" />
<asp:Button ID="btnCancel" runat="server" Text="Cancel"
   onclick="btnCancel_Click"/>
</div>

OfficeAddEdit.ascx.cs Page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace OfficeDelegate
{
   public partial class OfficeAddEdit : System.Web.UI.UserControl
   {
   public int TabID
   {
   get
   {
   if (ViewState["TabId"] == null)
   return 0;
   else
   return Convert.ToInt32(ViewState["TabId"]);
   }

   set
   {
   ViewState["TabId"] = value;
   }
   }
   public int OfficeId
   {
   get
   {
   if (ViewState["Id"] == null)
   return 0;
   else
   return Convert.ToInt32(ViewState["Id"]);
   }

   set
   {
   ViewState["Id"] = value;
   }
   }
   public event OfficeHandler eventhandler;
   protected void Page_Load(object sender, EventArgs e)
   {

   }

   protected void btnAdd_Click(object sender, EventArgs e)
   {

   if (Page.IsValid)
   {
   Insert();
   }

   }

   protected void btnCancel_Click(object sender, EventArgs e)
   {

   TabID = 1;
   eventhandler();


   }

   public void View()
   {
   if (OfficeId != 0)
   {
   SetTocotrol();
   }
   else
   {
   txtName.Text = string.Empty;
   txtCity.Text = string.Empty;
   txtCountry.Text = string.Empty;
   }
   }

   private void SetTocotrol()
   {
   OfficeDataContext db = new OfficeDataContext();
   Office office = (from l in db.Offices where l.OfficeId == OfficeId select l).FirstOrDefault();
   txtName.Text = office.OfficeName;
   txtCity.Text = office.City;
   txtCountry.Text = office.Country;
   }





   public void Insert()
   {
   if (OfficeId == 0)
   {
   OfficeDataContext db = new OfficeDataContext();
   var office = new Office { OfficeName = txtName.Text, City = txtCity.Text, Country = txtCountry.Text };
   db.Offices.InsertOnSubmit(office);
   db.SubmitChanges();
   TabID = 1;
   eventhandler();
   }
   else
   {
   OfficeDataContext db = new OfficeDataContext();
   Office office = (from l in db.Offices where l.OfficeId == OfficeId select l).FirstOrDefault();
   office.OfficeName = txtName.Text;
   office.City = txtCity.Text;
   office.Country = txtCountry.Text;
   //db.Offices.InsertOnSubmit(office);
   db.SubmitChanges();
   TabID = 1;
   eventhandler();
   }
   }
   }
}