How do I convert Twips to Pixels in .NET?

Question

I\'m working on a migration project in which a database actually stores display sizes in twips. Since I can\'t use twips to assign sizes to WPF or Winforms controls, I was w

Answer 1

For reference, another C# version, using the Win32 API instead of requiring a Graphics objects:

using System.Runtime.InteropServices;

static class SomeUtils {

  public static int ConvertTwipsToPixels(int twips, MeasureDirection direction) {
    return (int)(((double)twips)*((double)GetPixperinch(direction))/1440.0);
  }

  public static int ConvertPixelsToTwips(int pixels, MeasureDirection direction) {
    return (int)((((double)pixels)*1440.0)/((double)GetPixperinch(direction)));
  }

  public static int GetPPI(MeasureDirection direction) {
    int ppi;
    IntPtr dc = GetDC(IntPtr.Zero);

    if (direction == MeasureDirection.Horizontal)
      ppi = GetDeviceCaps(dc, 88); //DEVICECAP LOGPIXELSX
    else
      ppi = GetDeviceCaps(dc, 90); //DEVICECAP LOGPIXELSY

    ReleaseDC(IntPtr.Zero, dc);
    return ppi;
  }

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

  [DllImport("user32.dll")]
  static extern bool ReleaseDC(IntPtr hWnd, IntPtr hDC);

  [DllImport("gdi32.dll")]
  static extern int GetDeviceCaps(IntPtr hdc, int devCap);
}

public enum MeasureDirection {
  Horizontal,
  Vertical
}

The MeasureDirection is supposed to be specified as there is no guarantee that pixels are always square (according to the kb).

Reference: kb210590: ACC2000: How to Convert Twips to Pixels