public bool VirtualMode {get; set;}

using System;
using System.Windows.Forms;
using System.Collections.Generic;

namespace GrapeCity.Win.MultiRow.SampleCode
{
    public class VirtualModeDemo : Form
    {
        private GcMultiRow gcMultiRow1 = new GcMultiRow();
        private List<Student> userData = new List<Student>();
        private Student uncommitNewStudent = null;
        private Student restoreRow = null;

        public VirtualModeDemo()
        {
            this.Text = "VirtualMode Demo";

            // Add MultiRow to form
            this.gcMultiRow1.Dock = DockStyle.Fill;
            this.Controls.Add(this.gcMultiRow1);

            this.InitializeTemplate();

            this.InitializeData();

            this.Load += new EventHandler(Form1_Load);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // Set virtual mode event, you can manage date by you self by CellValueNeeded,CellValuePushed etc. events.
            gcMultiRow1.VirtualMode = true;
            gcMultiRow1.CellValueNeeded += new EventHandler<CellValueEventArgs>(gcMultiRow1_CellValueNeeded);
            gcMultiRow1.CellValuePushed += new EventHandler<CellValueEventArgs>(gcMultiRow1_CellValuePushed);
            gcMultiRow1.CancelRowEdit += new EventHandler<QuestionEventArgs>(gcMultiRow1_CancelRowEdit);
            gcMultiRow1.NewRowNeeded += new EventHandler<RowEventArgs>(gcMultiRow1_NewRowNeeded);
            gcMultiRow1.RowEnter += new EventHandler<CellEventArgs>(gcMultiRow1_RowEnter);
            gcMultiRow1.RowsAdded += new EventHandler<RowsAddedEventArgs>(gcMultiRow1_RowsAdded);
            gcMultiRow1.RowsRemoved += new EventHandler<RowsRemovedEventArgs>(gcMultiRow1_RowsRemoved);
        }

        void gcMultiRow1_CellValuePushed(object sender, CellValueEventArgs e)
        {
            // When user edit value, MultiRow control will notify update your data by this event.
            Student student = userData[e.RowIndex];

            if (e.CellName == "Name")
            {
                student.Name = e.Value.ToString();
            }
            else
            {
                int value;

                if (!int.TryParse(e.Value.ToString(), out value))
                {
                    MessageBox.Show("Score should be a number");
                    return;
                }

                if (e.CellName == "Mathematics")
                {
                    student.MathematicsScore = value;
                }
                else if (e.CellName == "Philosophy")
                {
                    student.PhilosophyScore = value;
                }
            }
        }

        void gcMultiRow1_CellValueNeeded(object sender, CellValueEventArgs e)
        {
            Student student = null;
            if (e.RowIndex == userData.Count)
            {
                student = uncommitNewStudent;
            }
            else
            {
                student = userData[e.RowIndex];
            }

            // When MultiRow control paint a cell, the control will ask the value of the specific cell by this event.
            if (e.CellName == "Name")
            {
                e.Value = student.Name;
            }
            if (e.CellName == "Mathematics")
            {
                e.Value = student.MathematicsScore;
            }
            if (e.CellName == "Philosophy")
            {
                e.Value = student.PhilosophyScore;
            }
            if (e.CellName == "ID")
            {
                e.Value = student.ID;
            }
        }

        void gcMultiRow1_NewRowNeeded(object sender, RowEventArgs e)
        {
            // Add new row when user move current cell to last new row.
            uncommitNewStudent = new Student(userData.Count, null, 0, 0);
        }

        void gcMultiRow1_CancelRowEdit(object sender, QuestionEventArgs e)
        {
            int currentRowIndex = gcMultiRow1.CurrentCellPosition.RowIndex;
            // Cancel uncommitted new row.
            if (currentRowIndex >= 0 && currentRowIndex < gcMultiRow1.RowCount - 1)
            {
                // Cancel row level edit.
                userData[currentRowIndex] = new Student(restoreRow.ID, restoreRow.Name, restoreRow.MathematicsScore, restoreRow.PhilosophyScore);
            }
        }

        void gcMultiRow1_RowsRemoved(object sender, RowsRemovedEventArgs e)
        {
            // When user select rows and press Ctrl+Delete key, the rows romoved.
            // Update user data source.
            userData.RemoveRange(e.RowIndex, e.RowCount);
        }

        void gcMultiRow1_RowsAdded(object sender, RowsAddedEventArgs e)
        {
            // When user add rows, add  uncommitted new row to user data source.
            userData.Add(uncommitNewStudent);
        }

        void gcMultiRow1_RowEnter(object sender, CellEventArgs e)
        {
            if (e.RowIndex != gcMultiRow1.NewRowIndex)
            {
                // When row enter cache old value, if user press ESC key to cancel row level edit value, use this row restore.
                restoreRow = new Student(userData[e.RowIndex].ID, userData[e.RowIndex].Name, userData[e.RowIndex].MathematicsScore, userData[e.RowIndex].PhilosophyScore);
            }
        }

        private void InitializeTemplate()
        {
            // Create a template with 3 text box and a header cell.
            Template template = Template.CreateGridTemplate(3);

            // Initialize column header's caption
            template.ColumnHeaders[0][0].Value = "Name";
            template.ColumnHeaders[0][1].Value = "Mathematics";
            template.ColumnHeaders[0][2].Value = "Philosophy";
            template.ColumnHeaders[0][3].Value = "ID";

            // Initialize cell's Name.
            template.Row.Cells[0].Name = "Name";
            template.Row.Cells[1].Name = "Mathematics";
            template.Row.Cells[2].Name = "Philosophy";
            template.Row.Cells[3].Name = "ID";

            this.gcMultiRow1.Template = template;
        }

        #region Initial user data

        public class Student
        {
            public Student(int id, string name, int mathematicsScore, int philosophyScore)
            {
                ID = id;
                Name = name;
                MathematicsScore = mathematicsScore;
                PhilosophyScore = philosophyScore;
            }

            public int ID;
            public string Name;
            public int MathematicsScore;
            public int PhilosophyScore;
        }

        private void InitializeData()
        {
            userData.Add(new Student(0, "Jim", 100, 100));
            userData.Add(new Student(1, "Tom", 88, 92));
            userData.Add(new Student(2, "Smith", 80, 66));

            // 3 records and a new row.
            this.gcMultiRow1.RowCount = 4;
        }

        #endregion

        [STAThreadAttribute()]
        public static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new VirtualModeDemo());
        }
    }
}