以编程方式更改屏幕方向(2)

using System.Runtime.InteropServices;

...

public class NativeMethods

{

// PInvoke declaration for EnumDisplaySettings Win32 API

[DllImport("user32.dll", CharSet=CharSet.Ansi)]

public static extern int EnumDisplaySettings(

string lpszDeviceName,

int iModeNum,

ref DEVMODE lpDevMode);         
// PInvoke declaration for ChangeDisplaySettings Win32 API

[DllImport("user32.dll, CharSet=CharSet.Ansi")]

public static extern int ChangeDisplaySettings(

ref DEVMODE lpDevMode,

int dwFlags);
// add more functions as needed ??
// constants

public const int ENUM_CURRENT_SETTINGS = -1;

public const int DMDO_DEFAULT = 0;

public const int DMDO_90 = 1;

public const int DMDO_180 = 2;

public const int DMDO_270 = 3;

// add more constants as needed ??

}

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]

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 int    dmPositionX;

public int    dmPositionY;

public int    dmDisplayOrientation;

public int    dmDisplayFixedOutput;

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;

};

public static DEVMODE CreateDevmode()

{

DEVMODE dm = new DEVMODE();

dm.dmDeviceName = new String(new char[32]);

dm.dmFormName = new String(new char[32]);

dm.dmSize = (short)Marshal.SizeOf(dm);

return dm;

}