unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

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

var
  Form1: TForm1;
  OldWinKuan,OldWinGao:INTEGER;    //获取当前窗体分辨率

implementation

{$R *.dfm}

//更改系统显示刷新频率
function   ChangeDisplay(width,height:word)   :BOOL   ;
var
        lpDevMode   :TDEVICEMODe   ;
begin
        result   :=   EnumDisplaySettings(Nil   ,0   ,lpDEVMode)   ;
        if   result   then
        begin
                lpDevmode.dmFields   :=   DM_PELSWIDTH   or   DM_PELSHEIGHT   ;
                lpdevmode.dmPelsWidth   :=   width   ;
                lpdevmode.dmPelsHeight   :=   height   ;
                result   :=   ChangeDisplaySettings(lpdevmode   ,CDS_UPDATEREGISTRY)   =   DISP_CHANGE_SUCCESSFUL   ;
        end;
end;

{上面的代码，在2000系统下执行，刷新频率为最低，所以必改刷新频率。以下为刷新率函数}

//获得当前系统显示刷新频率
{function   GetDispSet():integer;
var
    DeviceMode:   TDeviceMode;
begin
      result:=0;
      EnumDisplaySettings(nil,   Cardinal(-1),   DeviceMode);
      result:=DeviceMode.dmDisplayFrequency;
end;

//改变系统显示刷新频率
function   ChangeDispSet(iFrequency:integer):integer;
var
    DeviceMode:TDeviceMode;
begin
      result:=0;
      EnumDisplaySettings(nil,Cardinal(-1),   DeviceMode);
      DeviceMode.dmDisplayFrequency:=Cardinal(iFrequency);
      result:=ChangeDisplaySettings(DeviceMode,CDS_UPDATEREGISTRY);
end;   }


procedure TForm1.FormCreate(Sender: TObject);
begin

  OldWinKuan:=screen.Width;
  OldWinGao:=screen.Height;
if (screen.Width <> 1280) and (screen.Height <> 1024) then
Begin
 ChangeDisplay(1280,1024)        //修改屏幕分辨率为 1280*1024
End;

end;



procedure TForm1.FormDestroy(Sender: TObject);
begin

if (screen.Width <> OldWinKuan) and (screen.Height <> OldWinGao) then
Begin
 ChangeDisplay(OldWinKuan,OldWinGao)
End;

end;

end.