Reading and writing a pixel color to the API help

Import System.Drawing namespace ,System.Runtime.InteropServices and System.Windows.Forms namespace .

using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
[DllImport( "user32.dll" )]
static extern IntPtr GetDC( IntPtr hWnd );
[DllImport( "user32.dll" )]
static extern int ReleaseDC( IntPtr hWnd, IntPtr hDC );
[DllImport( "gdi32.dll" )]
static extern int GetPixel( IntPtr hDC, int x, int y );
[DllImport( "gdi32.dll" )]
static extern int SetPixel( IntPtr hDC, int x, int y, int color );

static public Color GetPixel( Control control, int x, int y )
{
    Color color = Color.Empty;
    if (control != null)
    {
        IntPtr hDC = GetDC( control.Handle );
        int colorRef = GetPixel( hDC, x, y );
        color = Color.FromArgb(
            (int)(colorRef & 0x000000FF),
            (int)(colorRef & 0x0000FF00) >> 8,
            (int)(colorRef & 0x00FF0000) >> 16 );
        ReleaseDC( control.Handle, hDC );
    }
    return color;
}
static public void SetPixel( Control control, int x, int y, Color color )
{
    if (control != null)
    {
        IntPtr hDC = GetDC( control.Handle );
        int argb = color.ToArgb();
        int colorRef =
            (int)((argb & 0x00FF0000) >> 16) |
            (int)(argb & 0x0000FF00) |
            (int)((argb & 0x000000FF) << 16);
        SetPixel( hDC, x, y, colorRef );
        ReleaseDC( control.Handle, hDC );
    }
}