pinvoke.net: Edit: gdi32.setdevicegammaramp

@msdn=http://search.microsoft.com/search/results.aspx?qu=$$$
@pinvoke=http://pinvoke.net/$$$.htm

Summary: The SetDeviceGammaRamp API

!!!!C# Signature:
 [DllImport("gdi32.dll")]
 public static extern bool SetDeviceGammaRamp(IntPtr hDC, ref RAMP lpRamp);
!!!!User-Defined Types:
 [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)] 
 public struct RAMP
 {
  [ MarshalAs(UnmanagedType.ByValArray, SizeConst=256)] 
  public UInt16[] Red;
  [ MarshalAs(UnmanagedType.ByValArray, SizeConst=256)] 
  public UInt16[] Green;
  [ MarshalAs(UnmanagedType.ByValArray, SizeConst=256)] 
  public UInt16[] Blue;
 }

!!!!Notes:
You need to define a 256 color "RAMP" to set this api. Check example for explanation.
2. Values from 1 to 256 are supported.
3. Also include this signature:
[DllImport("user32.dll")]
public static extern IntPtr GetDC(IntPtr hWnd);
!!!!Tips & Tricks:
Please add some!

!!!!Sample Code:
 using System.Collections;
 using System;
 using System.Drawing;
 using System.Runtime.InteropServices;
 using System.Windows.Forms;
 public class Test{

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

[DllImport("gdi32.dll")]
 public static extern bool SetDeviceGammaRamp(IntPtr hDC, ref RAMP lpRamp);

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)] 
 public struct RAMP
 {
  [ MarshalAs(UnmanagedType.ByValArray, SizeConst=256)] 
  public UInt16[] Red;
  [ MarshalAs(UnmanagedType.ByValArray, SizeConst=256)] 
  public UInt16[] Green;
  [ MarshalAs(UnmanagedType.ByValArray, SizeConst=256)] 
  public UInt16[] Blue;
 }

public static void SetGamma(int gamma)
 {
  if (gamma <= 256 && gamma >= 1)
  {
   RAMP ramp = new RAMP();
   ramp.Red = new ushort[256];
   ramp.Green = new ushort[256];
   ramp.Blue = new ushort[256];
   for( int i=1; i<256; i++ )
   {
    int iArrayValue = i * (gamma + 128);

if (iArrayValue > 65535)
	iArrayValue = 65535;
    ramp.Red[i] = ramp.Blue[i] = ramp.Green[i] = (ushort)iArrayValue;
   }
   SetDeviceGammaRamp(GetDC(IntPtr.Zero), ref ramp);
  }
  }
 
 public static void Main(string[] args)
 {
  string ent = "";
  int g=0;
  while (ent != "EXIT")
   {
    Console.WriteLine("Enter new Gamma (or 'EXIT' to quit):");
    ent = Console.ReadLine();
    try{
    g=int.Parse(ent);
    SetGamma(g);
    }
    catch{
	//Here only to catch errors where input is not a number (EXIT, for example, is a string)		
    }
   }
 }
 }

!!!!Alternative Managed API:

Documentation: SetDeviceGammaRamp@msdn on MSDN