This example just shows the combination of the above 3 basic samples (Edit, Add, Delete) in a single grid. It can be used for reference and easy starting point when creating a grid with CRUD (Create, Read, Update,Delete) operations enabled.

Take a look at the C# code file for implementation details.
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="default.aspx.cs" Inherits="JQSuiteASPNETExample.examples.editing_data.edit_add_delete._default" %>
<%@ Register Assembly="Trirand.Web" TagPrefix="trirand" Namespace="Trirand.Web.UI.WebControls" %>

<!DOCTYPE html>
<html lang="en-us">
<head id="Head1" runat="server">
    <meta charset="utf-8">
    <title>jqGrid for ASP.NET WebForms - edit add and delete dialogs</title>
    <!-- The jQuery UI theme that will be used by the grid -->
    <link rel="stylesheet" type="text/css" media="screen" href="http://code.jquery.com/ui/1.12.1/themes/redmond/jquery-ui.css" />
    <!-- The jQuery UI theme extension jqGrid needs -->
    <link rel="stylesheet" type="text/css" media="screen" href="/themes/ui.jqgrid.css" />
    <!-- jQuery runtime minified -->
    <script src="/js/jquery-3.2.1.min.js" type="text/javascript"></script>
    <!-- The localization file we need, English in this case -->
    <script src="/js/trirand/i18n/grid.locale-en.js" type="text/javascript"></script>
    <!-- The jqGrid client-side javascript -->
    <script src="/js/trirand/jquery.jqGrid.min.js" type="text/javascript"></script>    
    
    <style type="text/css">
        body, html { font-size: 80%; }    
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div>       
       <div id="message"></div>
       
       <script type="text/javascript">

           function addRow() {
               var grid = jQuery("#<%= JQGrid1.ClientID %>");
               grid.editGridRow("new", grid.addDialogOptions);
           }

           function editRow() {
               var grid = jQuery("#<%= JQGrid1.ClientID %>");
               var rowKey = grid.getGridParam("selrow");
               var editOptions = grid.getGridParam('editDialogOptions');
               if (rowKey) {
                   grid.editGridRow(rowKey, editOptions);
               }
               else {
                   alert("No rows are selected");
               }
           }

           function delRow() {
               var grid = jQuery("#<%= JQGrid1.ClientID %>");
               var rowKey = grid.getGridParam("selrow");
               if (rowKey) {
                   grid.delGridRow(rowKey, grid.delDialogOptions);
               }
               else {
                   alert("No rows are selected");
               }
           }
       </script>
       
       <input type="button" onclick="addRow()" value="Add" />
       <input type="button" onclick="editRow()" value="Edit" />
       <input type="button" onclick="delRow()" value="Delete" />
       
       <trirand:JQGrid ID="JQGrid1" runat="server" Width="600px"  
            OnRowDeleting="JQGrid1_RowDeleting"
            OnRowAdding="JQGrid1_RowAdding"
            OnRowEditing="JQGrid1_RowEditing">         
            <Columns>
                <trirand:JQGridColumn DataField="CustomerID" Editable="false" PrimaryKey="true" />
                <trirand:JQGridColumn DataField="CompanyName" Editable="true" />
                <trirand:JQGridColumn DataField="Phone" Editable="true" />
                <trirand:JQGridColumn DataField="PostalCode" Editable="true" />
                <trirand:JQGridColumn DataField="City" Editable="true" />                
            </Columns>
            <ToolBarSettings ShowEditButton="true" ShowAddButton="true" ShowDeleteButton="true" />
            <EditDialogSettings CloseAfterEditing="true" Caption="The Edit Dialog"  />
            <AddDialogSettings CloseAfterAdding="true" />                   
       </trirand:JQGrid>     

       
       <br /><br />
       <trirand:codetabs runat="server" id="DataTableCodeTabs"></trirand:codetabs>
       
    </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.Data.SqlClient;
using System.Data;
using System.Configuration;

namespace JQSuiteASPNETExample.examples.editing_data.edit_add_delete
{
    public partial class _default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            JQGrid1.DataSource = GetData();
            JQGrid1.DataBind();
        }

        protected void JQGrid1_RowAdding(object sender, Trirand.Web.UI.WebControls.JQGridRowAddEventArgs e)
        {
            DataTable dt = GetData();
            DataRow row = dt.NewRow();

            row["CustomerID"] = "NEW" + dt.Rows.Count.ToString();
            row["CompanyName"] = e.RowData["CompanyName"];
            row["Phone"] = e.RowData["Phone"];
            row["PostalCode"] = e.RowData["PostalCode"];
            row["City"] = e.RowData["City"];

            dt.Rows.InsertAt(row, 0);
        }

        protected void JQGrid1_RowEditing(object sender, Trirand.Web.UI.WebControls.JQGridRowEditEventArgs e)
        {
            DataTable dt = GetData();
            dt.PrimaryKey = new DataColumn[] { dt.Columns["CustomerID"] };
            DataRow rowEdited = dt.Rows.Find(e.RowKey);

            rowEdited["CompanyName"] = e.RowData["CompanyName"];
            rowEdited["Phone"] = e.RowData["Phone"];
            rowEdited["PostalCode"] = e.RowData["PostalCode"];
            rowEdited["City"] = e.RowData["City"];
        }

        protected void JQGrid1_RowDeleting(object sender, Trirand.Web.UI.WebControls.JQGridRowDeleteEventArgs e)
        {            
            DataTable dt = GetData();
            dt.PrimaryKey = new DataColumn[] { dt.Columns["CustomerID"] };
            DataRow rowToDelete = dt.Rows.Find(e.RowKey);

            if (rowToDelete != null)
                dt.Rows.Remove(rowToDelete);

            JQGrid1.DataSource = GetData();
            JQGrid1.DataBind();
        } 

        protected DataTable GetData()
        {
            if (Session["EditDialogData"] == null)
            {
                // Create a new Sql Connection and set connection string accordingly
                SqlConnection sqlConnection = new SqlConnection();
                sqlConnection.ConnectionString = ConfigurationManager.ConnectionStrings["SQL2008_661086_trirandEntities"].ConnectionString;
                sqlConnection.Open();

                string sqlStatement = "SELECT CustomerID, CompanyName, Phone, PostalCode, City FROM Customers";

                // Create a SqlDataAdapter to get the results as DataTable
                SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(sqlStatement, sqlConnection);

                // Create a new DataTable
                DataTable dtResult = new DataTable();

                // Fill the DataTable with the result of the SQL statement
                sqlDataAdapter.Fill(dtResult);

                Session["EditDialogData"] = dtResult;

                return dtResult;
            }
            else
            {
                return Session["EditDialogData"] as DataTable;
            }
        }    
    }
}
Switch theme:


Theming is based on the very popular jQuery ThemeRoller standard. This is the same theming mechanism used by jQuery UI and is now a de-facto standard for jQuery based components. The benefits of using ThemeRoller are huge. We can offer a big set of ready to use themes created by professional designers, including Windows-like themes (Redmond), Apple-like theme (Cupertino), etc. In addition to that any jQuery UI controls on the same page will pick the same theme.

Last, but not least, you can always roll your own ThemeRoller theme, using the superb Theme Editor

To use a theme, simply reference 2 Css files in your Html <head> section - the ThemeRoller theme you wish to use, and the jqGrid own ThemeRoller Css file. For example (Redmond theme):

<link rel="stylesheet" type="text/css" media="screen" href="/themes/redmond/jquery-ui-1.8.2.custom.css" />
<link rel="stylesheet" type="text/css" media="screen" href="/themes/ui.jqgrid.css" />