Dynamic control using repeater

Here we add dynamic controls using repeater control and view state. On click on add new button a new row is add and new record add to datatable save in view state of page.

Default.aspx

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"

    CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">

</asp:Content>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

  <asp:ScriptManager ID="scriptManager" runat="server"></asp:ScriptManager>

<asp:UpdatePanel ID="upPanael" runat="server">

    <ContentTemplate>

        <div>

                                                                                                                                                                                                                                           <div>

            <table>

                <tr>

                    <th>

                        &nbsp;

                    </th>

                    <th>

                        Employee Name

                    </th>

                    <th>

                        Adderss

                    </th>

                    <th>

                        City

                    </th>

                    <th>

                        Email

                    </th>

                </tr>

                 <asp:Repeater ID="rptEmployee" runat="server">

                        <ItemTemplate>

                          <tr>

                            <td>

                                 &nbsp;

                            </td>

                            <td>

                                <asp:TextBox ID="TextBox1" runat="server" Width="150px" MaxLength="50" Text='<%# Eval("EmpName") %>'></asp:TextBox>

                            </td>

                            <td>

                                 <asp:TextBox ID="TextBox2" runat="server" Width="150px" MaxLength="50" Text='<%# Eval("Address") %>'></asp:TextBox>

                            </td>

                            <td>

                                <asp:TextBox ID="TextBox3" runat="server" Width="150px" MaxLength="50" Text='<%# Eval("City") %>'></asp:TextBox>

                            </td>

                            <td>

                                 <asp:TextBox ID="TextBox4" runat="server" Width="150px" MaxLength="50" Text='<%# Eval("Email") %>'></asp:TextBox>

                            </td>

                        </tr>

                     </ItemTemplate>

                   </asp:Repeater>

                <tr>

                    <td>

                       <asp:Button ID="btnAdd" runat="server" Text="Add New" onclick="btnAdd_Click" />

                    </td>

                    <td>

                        <asp:TextBox ID="txtEmpName" runat="server" Width="150px" MaxLength="50"></asp:TextBox>

                    </td>

                    <td>

                         <asp:TextBox ID="txtAddress" runat="server" Width="150" MaxLength="50"></asp:TextBox>

                    </td>

                    <td>

                        <asp:TextBox ID="txtCity" runat="server" Width="150px" MaxLength="50"></asp:TextBox>

                    </td>

                    <td>

                         <asp:TextBox ID="txtEmail" runat="server" Width="150px" MaxLength="50"></asp:TextBox>

                    </td>

                </tr>

                  

            </table>

        </div>

        </div>

    </ContentTemplate>

</asp:UpdatePanel>

</asp:Content>

Default.aspx.cs

using System;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data;

public partial class _Default : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

    }

    protected void btnAdd_Click(object sender, EventArgs e)

    {

        DataTable dtEmployee = new DataTable();

        dtEmployee = GetEmployee();

        if (ViewState["EmployeeTable"] != null)

        {

            dtEmployee = (DataTable)ViewState["EmployeeTable"];

            rptEmployee.DataSource = dtEmployee;

            rptEmployee.DataBind();

            rptEmployee.Visible = true;

        }

        else

        {

            rptEmployee.DataSource = null;

            rptEmployee.DataBind();

            rptEmployee.Visible = false;

        }

        txtEmpName.Text = string.Empty;

        txtEmail.Text = string.Empty;

        txtCity.Text = string.Empty;

        txtAddress.Text = string.Empty;

    }

    private DataTable GetEmployee()

    {

        DataTable dtEmployee = null;

        if (ViewState["EmpID"] != null)

        {

            int EmpID = Convert.ToInt32((ViewState["EmpID"]));

            EmpID++;

            ViewState["EmpID"] = EmpID;

        }

        else

        {

            ViewState["EmpID"] = 1;

        }

        if (ViewState["EmployeeTable"] == null)

        {

            dtEmployee = new DataTable("EmployeeTable");

            dtEmployee.Columns.Add(new DataColumn("EmpID", typeof(int)));

            dtEmployee.Columns.Add(new DataColumn("EmpName", typeof(string)));

            dtEmployee.Columns.Add(new DataColumn("Address", typeof(string)));

            dtEmployee.Columns.Add(new DataColumn("City", typeof(string)));

            dtEmployee.Columns.Add(new DataColumn("Email", typeof(string)));

            ViewState["EmployeeTable"] = dtEmployee;

        }

        else

        {

            dtEmployee = (DataTable)ViewState["EmployeeTable"];

        }

        DataRow dtRow = dtEmployee.NewRow();

        dtRow["EmpID"] = Convert.ToInt32(ViewState["EmpID"]);

        dtRow["EmpName"] = txtEmpName.Text.Trim();

        dtRow["Address"] = txtAddress.Text.Trim();

        dtRow["City"] = txtCity.Text.Trim();

        dtRow["Email"] = txtEmail.Text.Trim();

        dtEmployee.Rows.Add(dtRow);

        ViewState["EmployeeTable"] = dtEmployee;

        return dtEmployee;

    }

}

Result