C#

PointF ConvertMillimtersToPixel(Graphics grfx, PointF pointF)
{
    pointF.X *= grfx.DpiX / 25.4f;
    pointF.Y *= grfx.DpiY /25.4f;

    return pointF;
}

public sealed class Display
{
  static Display()
  {
    SystemEvents.DisplaySettingsChanged += new EventHandler(Update);
  }
  private Display() {} // Prevent instantiation

  [DllImport("gdi32.dll")]
  private static extern IntPtr GetDeviceCaps(IntPtr hdc, IntPtr index);

  [DllImport("user32.dll")]
  private static extern IntPtr GetDC(IntPtr hwnd);

  [DllImport("user32.dll")]
  private static extern IntPtr ReleaseDC(IntPtr hwnd, IntPtr hdc);

  private static void Update(object sender, EventArgs e)
  {
    Setup(true);
  }
  private static void Setup(bool force)
  {
    if (initialized && !force) return;
    twipsPerPixelX  = twipsPerPixelY = 0; // Initial values
    IntPtr hdc = GetDC(IntPtr.Zero);
    try
    {
      if (!hdc.Equals(IntPtr.Zero))
      {
        IntPtr value;
        value = GetDeviceCaps(hdc, new IntPtr(88)); // LOGPIXELSX
        twipsPerPixelX = 1440 / value.ToInt32();
        value = GetDeviceCaps(hdc, new IntPtr(90)); // LOGPIXELSY
        twipsPerPixelY = 1440 / value.ToInt32();
        ReleaseDC(IntPtr.Zero, hdc);
      }
    }
    catch {}
    if (twipsPerPixelX == 0) twipsPerPixelX = 15; // Default for 96 DPI
    if (twipsPerPixelY == 0) twipsPerPixelY = 15; // Default for 96 DPI
    initialized = true;
  }
  private static bool initialized;
  private static int twipsPerPixelX;
  private static int twipsPerPixelY;
  public static int TwipsPerPixelX
  {
    get
    {
      Setup(false);
      return twipsPerPixelX;
    }
  }
  public static int TwipsPerPixelY
  {
    get
    {
      Setup(false);
      return twipsPerPixelY;
    }
  }
  public static int FromPixelsX(int x, ScaleMode mode)
  {
    switch (mode)
    {
      case ScaleMode.Points:
        return PixelsToTwipsX(x) / 20;
      case ScaleMode.Inches:
        return PixelsToTwipsX(x) / 1440;
      default:
        throw new ArgumentException("Invalid scale mode.", "mode");
    }
  }
  public static int FromPixelsY(int y, ScaleMode mode)
  {
    switch (mode)
    {
      case ScaleMode.Points:
        return PixelsToTwipsY(y) / 20;
      case ScaleMode.Inches:
        return PixelsToTwipsY(y) / 1440;
      default:
        throw new ArgumentException("Invalid scale mode.", "mode");
    }
  }
  public static int ToPixelsX(int x, ScaleMode mode)
  {
    switch (mode)
    {
      case ScaleMode.Points:
        return TwipsToPixelsX(x * 20);
      case ScaleMode.Inches:
        return TwipsToPixelsX(x * 1440);
      default:
        throw new ArgumentException("Invalid scale mode.", "mode");
    }
  }
  public static int ToPixelsY(int y, ScaleMode mode)
  {
    switch (mode)
    {
      case ScaleMode.Points:
        return TwipsToPixelsY(y * 20);
      case ScaleMode.Inches:
        return TwipsToPixelsY(y * 1440);
      default:
        throw new ArgumentException("Invalid scale mode.", "mode");
    }
  }
  public static int PixelsToTwipsX(int x)
  {
    Setup(false);
    return x * twipsPerPixelX;
  }
  public static int PixelsToTwipsY(int y)
  {
    Setup(false);
    return y * twipsPerPixelY;
  }
  public static int TwipsToPixelsX(int x)
  {
    Setup(false);
    return x / twipsPerPixelX;
  }
  public static int TwipsToPixelsY(int y)
  {
    Setup(false);
    return y / twipsPerPixelY;
  }
}

// A couple of examples
public enum ScaleMode
{
  Points,
  Inches
}

public class A
{
  protected SomeEnum e;
}
public class B : A
{
  public SomeEnum E
  {
    get { return base.e; } // this.e or just e will also work
    set { base.e = value; }
  }
}

"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

The Second EuroCPian Event will be in Brussels on the 4th of September

Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!

My Blog

"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

The Second EuroCPian Event will be in Brussels on the 4th of September

Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!

My Blog