C#

dgvSchedule.DoDragDrop(text, DragDropEffects.Copy); 
if (bDataDrop == true) 
{ 
           dgvSchedule.Rows[info.RowIndex].Cells[info.ColumnIndex].Value = null;         //setting the value to null 
           dgvSchedule.Rows[info.RowIndex].Cells[info.ColumnIndex].Selected = false;   //setting that cell to not selected 
           bDataDrop = false;                
} 

//Form1.cs--------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace ScreenSaver
{
    public partial class Form1 : Form
    {


        private int screenNumber;
        private Point MouseXY;
        int curX = 1;
        int curY = 1;
        Boolean running = true;

        public Form1(int screen)
        {
            screenNumber = screen;

            InitializeComponent();
            this.run();
           
        }
        private void form1_Load(object sender, System.EventArgs e)
        {
            this.Bounds = Screen.AllScreens[screenNumber].Bounds;
            Cursor.Hide();
            TopMost = true;
           
        }
        private void onMouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if (!MouseXY.IsEmpty)
            {
                if(MouseXY != new Point(e.X,e.Y))
                {
                    running = false;
                }
                if(e.Clicks >0)
                {
                    running = false;
                }
            }
            MouseXY = new Point(e.X, e.Y);
           
        }
       public void run()
        {
                while (running)
                {
                    loopMove();
                    Thread.Sleep(1000);
                }

                Close();
        }

        private void LM_Click(object sender, EventArgs e)
        {

        }
        private void changeLMY(int y)
        {
            LM.Left += y;

        }
        private void changeLMX(int x)
        {
            LM.Top += x;
        }
        private void loopMove()
        {
            int fX = this.Top;
            int fY = this.Left;
            if (LM.Top >= fX - 300)
                curX = -1;
            if (LM.Top == 0)
                curX = 1;
            if (LM.Left >= fY - 300)
                curY = -1;
            if (LM.Left == 0)
                curY = 1;
            changeLMX(curX);
            changeLMY(curY);

        }
    }
}
//---------------------------------------------------------------------------------------- end Form1

// Program.cs----------------------------------------------------------------------------------------------

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

namespace ScreenSaver
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main(String[] args)
        {
            if (args.Length > 0)
            {
                if (args[0].ToLower().Trim().Substring(0, 2) == "/c")
                {
                }
                else if(args[0].ToLower()== "/s")
                {
                }
                else if (args[0].ToLower() == "/p")
                {
                }
              

            }
            else
            {
                for (int i = Screen.AllScreens.GetLowerBound(0); i <= Screen.AllScreens.GetLowerBound(0); i++)
                {
                    System.Windows.Forms.Application.Run(new Form1(i));
                }
            }
        }

//end program.cs

Assembly myAssembly = Assembly.GetExecutingAssembly();
Bitmap mybit = new Bitmap(myAssembly.GetManifestResourceStream("UserControl_Page.images.error.jpg"));
Image img = Image.FromHbitmap(mybit.GetHbitmap());
ToolStripStatusLabel_InfoBottom.Image = img;

".\subfolder\file.xyz"
Application.StartupPath.tostring() + "file.xyz"

System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form_Main));
ToolStripStatusLabel_InfoBottom.Image = ((Image)(resources.GetObject("error.png")));

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

class test
{
    [STAThreadAttribute()]
    public static void Main()
    {
        Application.Run(new VirtualModeForm());
    }
}

class VirtualModeForm : Form
{
    private List<DataObject> m_Data = new List<DataObject>();
    private List<bool> m_Visited = new List<bool>();
    DataGridView m_Grid = new DataGridView();
    public VirtualModeForm()
    {
        Controls.Add(m_Grid);
        m_Grid.CellValueNeeded += OnCellValueNeeded;
        InitData();
        InitGrid();
    }

    private void InitData()
    {
        for (int i = 0; i < 1000001 + 1; i++)
        {
            m_Visited.Add(false);
            DataObject obj = new DataObject();
            obj.Id = i;
            obj.Val = 2 * i;
            m_Data.Add(obj);
        }
    }

    private void InitGrid()
    {
        m_Grid.Dock = DockStyle.Fill;
        m_Grid.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.DisplayedCellsExceptHeader);
        m_Grid.VirtualMode = true;
        m_Grid.ReadOnly = true;
        m_Grid.ColumnCount = 108;
        // this line causes 8 seconds delay. how to fix.
        m_Grid.RowCount = 1000000;
    }

    private void OnCellValueNeeded(object sender, DataGridViewCellValueEventArgs e)
    {

        m_Visited[e.RowIndex] = true;
        if (e.ColumnIndex == 0)
        {
            e.Value = m_Data[e.RowIndex].Id;
        }
        else if (e.ColumnIndex == 1)
        {
            e.Value = m_Data[e.RowIndex].Val;
        }
        else if (e.ColumnIndex == 2)
        {

            Random rand = new Random();
            e.Value = rand.Next();
        }
    }
}

public class DataObject
{
    private int m_Id;
    private int m_Val;

    public int Val
    {
        get { return m_Val; }
        set { m_Val = value; }
    }

    public int Id
    {
        get { return m_Id; }
        set { m_Id = value; }
    }

    public int Id1 { get; set; }
    public int Id2 { get; set; }
    public int Id3 { get; set; }
    public int Id4 { get; set; }
    public int Id5 { get; set; }
    public int Id6 { get; set; }
    public int Id7 { get; set; }
    public int Id8 { get; set; }
    public int Id9 { get; set; }
    public int Id10 { get; set; }
    public int Id11 { get; set; }
    public int Id12 { get; set; }
    public int Id13 { get; set; }
    public int Id14 { get; set; }
    public int Id15 { get; set; }
    public int Id16 { get; set; }
    public int Id17 { get; set; }
    public int Id18 { get; set; }
    public int Id19 { get; set; }
    public int Id20 { get; set; }
    public int Id21 { get; set; }
    public int Id22 { get; set; }
    public int Id23 { get; set; }
    public int Id24 { get; set; }
    public int Id25 { get; set; }
    public int Id26 { get; set; }
    public int Id27 { get; set; }
    public int Id28 { get; set; }
    public int Id29 { get; set; }
    public int Id31 { get; set; }
    public int Id32 { get; set; }
    public int Id33 { get; set; }
    public int Id34 { get; set; }
    public int Id35 { get; set; }
    public int Id36 { get; set; }
    public int Id37 { get; set; }
    public int Id38 { get; set; }
    public int Id39 { get; set; }
    public int Id310 { get; set; }
    public int Id311 { get; set; }
    public int Id312 { get; set; }
    public int Id313 { get; set; }
    public int Id314 { get; set; }
    public int Id315 { get; set; }
    public int Id316 { get; set; }
    public int Id317 { get; set; }
    public int Id318 { get; set; }
    public int Id319 { get; set; }
    public int Id320 { get; set; }
    public int Id321 { get; set; }
    public int Id322 { get; set; }
    public int Id323 { get; set; }
    public int Id324 { get; set; }
    public int Id325 { get; set; }
    public int Id326 { get; set; }
    public int Id327 { get; set; }
    public int Id328 { get; set; }
    public int Id329 { get; set; }


    public int Id401 { get; set; }
    public int Id402 { get; set; }
    public int Id403 { get; set; }
    public int Id404 { get; set; }
    public int Id405 { get; set; }
    public int Id406 { get; set; }
    public int Id407 { get; set; }
    public int Id408 { get; set; }
    public int Id409 { get; set; }
    public int Id4010 { get; set; }
    public int Id4011 { get; set; }
    public int Id4012 { get; set; }
    public int Id4013 { get; set; }
    public int Id4014 { get; set; }
    public int Id4015 { get; set; }
    public int Id4016 { get; set; }
    public int Id4017 { get; set; }
    public int Id4018 { get; set; }
    public int Id4019 { get; set; }
    public int Id4020 { get; set; }
    public int Id4021 { get; set; }
    public int Id4022 { get; set; }
    public int Id4023 { get; set; }
    public int Id4024 { get; set; }
    public int Id4025 { get; set; }
    public int Id4026 { get; set; }
    public int Id4027 { get; set; }
    public int Id4028 { get; set; }
    public int Id4029 { get; set; }
    public int Id4031 { get; set; }
    public int Id4032 { get; set; }
    public int Id4033 { get; set; }
    public int Id4034 { get; set; }
    public int Id4035 { get; set; }
    public int Id4036 { get; set; }
    public int Id4037 { get; set; }
    public int Id4038 { get; set; }
    public int Id4039 { get; set; }
    public int Id40310 { get; set; }
    public int Id40311 { get; set; }
    public int Id40312 { get; set; }
    public int Id40313 { get; set; }
    public int Id40314 { get; set; }
    public int Id40315 { get; set; }
    public int Id40316 { get; set; }
    public int Id40317 { get; set; }
    public int Id40318 { get; set; }
    public int Id40319 { get; set; }
    public int Id40320 { get; set; }
    public int Id40321 { get; set; }
    public int Id40322 { get; set; }
    public int Id40323 { get; set; }
    public int Id40324 { get; set; }
    public int Id40325 { get; set; }
    public int Id40326 { get; set; }
    public int Id40327 { get; set; }
    public int Id40328 { get; set; }
    public int Id40329 { get; set; }
}