屏幕亮度(XE10.1+WIN8.164)

相关资料：

http://bbs.csdn.net/topics/390664310

实例代码：

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Imaging.jpeg,
  Vcl.ExtCtrls;

type
  TRampArray = array[0..2] of array[byte] of word;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Image1: TImage;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  origRampArray: TRampArray;

implementation

{$R *.dfm}

function SetBrightness(wBrightness: word): boolean;
var
  RampArray: TRampArray;
  I, Value: integer;
  DC: HDC;
begin
  for I := 0 to MAXBYTE do
  begin
    Value := I * (wBrightness + 128);
    if (Value > MAXWORD) then Value := MAXWORD;
    RampArray[0][I] := Value;
    RampArray[1][I] := Value;
    RampArray[2][I] := Value;
  end;
  DC := GetDC(0);
  try
    Result := SetDeviceGammaRamp(DC, RampArray);
  finally
    ReleaseDC(0, DC);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  SetBrightness(64);
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  DC: HDC;
begin
  DC := GetDC(0);
  try
    SetDeviceGammaRamp(DC, origRampArray);
  finally
    ReleaseDC(0, DC);
  end
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  DC: HDC;
begin
  DC := GetDC(0);
  try
    GetDeviceGammaRamp(DC, origRampArray);
  finally
    ReleaseDC(0, DC);
  end
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  Button2Click(Button2);
end;

end.