private void CalculateWideOfColomn(Graphics g)

        {

            SizeF tmpSize = new SizeF();

            for (int i = 0; i <= dataGridView1.Columns.Count - 1; i++)

            {

                Font tmpFont = dataGridView1.DefaultCellStyle.Font;

                tmpSize = g.MeasureString(dataGridView1.Columns[i].HeaderText, tmpFont);

                float tmpWidth = tmpSize.Width;

                float RowHeaderHeight = tmpSize.Height;

                for (int j = 0; j <= dataGridView1.Rows.Count - 1; j++)

                {

                    tmpSize = g.MeasureString("HELLO", tmpFont);

                    tmpSize = g.MeasureString(dataGridView1.Rows[j].Cells[i].EditedFormattedValue.ToString(), tmpFont);

                    if (tmpSize.Width > tmpWidth)

                    {

                        tmpWidth = tmpSize.Width;

                    }

                }

                if (dataGridView1.Columns[i].Visible)

                    dataGridView1.Columns[i].Width = (int)tmpWidth;

            }

}

using System.Runtime.InteropServices;

       //بررسی اتصال به اینترنت

    [DllImport("wininet.dll")]       

    private extern static bool InternetGetConnectedState(out int Description, int ReservedValue);

    //Creating a function that uses the API function...

   bool IsConnectedToInternet()

    {

        bool a;

        int Desc;

        a=InternetGetConnectedState(out Desc, 0);

        return a;

    }

private void textBox1_KeyDown(object sender, KeyEventArgs e)

{

    if (e.KeyCode == Keys.Return)

        SendKeys.Send("{TAB}");

}

String ucode = String.Format("{0:x4}", (int)('a'));

// ucode = 0061

String acode = (((int)('a')).ToString());

//acode=97

using System.Drawing;

using System.Drawing.Drawing2D;

using System.Runtime.InteropServices;         

[DllImport("user32")]

internal static extern IntPtr GetDC(IntPtr hwnd);

[DllImport("User32.dll")]

internal static extern void ReleaseDC(IntPtr dc);

public void PaintRectangleToScreen()

{

    IntPtr deskDC = GetDC(IntPtr.Zero);

    Graphics g = Graphics.FromHdc(deskDC);

    Font font = new Font("Arial Black", 36);                

    DrawStringOnCenter(g, "Sale 1387 mobarak!", font, new Point(0, -25));

    font = new Font("Arial Black", 18);

    DrawStringOnCenter(g, "by: Sinpin", font, new Point(0, 25));

    Rectangle rect = new Rectangle(200, 300,

        Screen.PrimaryScreen.Bounds.Width - 400,

        Screen.PrimaryScreen.Bounds.Height - 600);

    g.FillRectangle(new SolidBrush(Color.FromArgb(100, Color.DodgerBlue))

    , rect);

    g.DrawRectangle(new Pen(Color.DodgerBlue, 3), rect);

    g.Dispose();

    ReleaseDC(deskDC);

}

private void DrawStringOnCenter(Graphics g, string str, Font font, Point offset)

{

    SizeF size = g.MeasureString(str, font);

    g.DrawString(str, font, Brushes.White,

      new PointF(

        (Screen.PrimaryScreen.Bounds.Width - size.Width) / 2 + offset.X,

        (Screen.PrimaryScreen.Bounds.Height - size.Height) / 2 + offset.Y)

        );

}

private void Form1_Load(object sender, EventArgs e)

{

    PaintRectangleToScreen();

    this.Close();