C# Signature:

[DllImport("user32.dll")]

    public static extern int ChangeDisplaySettings(
          ref DEVMODE devMode, int flags);

User-Defined Types:

public struct DEVMODE

{

    [MarshalAs(UnmanagedType.ByValTStr,SizeConst=32)] public string dmDeviceName;
    public short  dmSpecVersion;
    public short  dmDriverVersion;
    public short  dmSize;
    public short  dmDriverExtra;
    public int    dmFields;

    public short dmOrientation;
    public short dmPaperSize;
    public short dmPaperLength;
    public short dmPaperWidth;

    public short dmScale;
    public short dmCopies;
    public short dmDefaultSource;
    public short dmPrintQuality;
    public short dmColor;
    public short dmDuplex;
    public short dmYResolution;
    public short dmTTOption;
    public short dmCollate;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string dmFormName;
    public short dmLogPixels;
    public short dmBitsPerPel;
    public int   dmPelsWidth;
    public int   dmPelsHeight;

    public int   dmDisplayFlags;
    public int   dmDisplayFrequency;

    public int   dmICMMethod;
    public int   dmICMIntent;
    public int   dmMediaType;
    public int   dmDitherType;
    public int   dmReserved1;
    public int   dmReserved2;

    public int   dmPanningWidth;
    public int   dmPanningHeight;

};

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

http://www.codeproject.com/csharp/CSDynamicScrRes.asp?df=100&forumid=38736&select=800137

Alternative Managed API:

Do you know one? Please contribute it!