unit1.pas

Delphi实效编程百例的随书源代码 这是其中的操作系统部分

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    TrackBar1: TTrackBar;
    Button1: TButton;
    Button2: TButton;
    procedure TrackBar1Change(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    //user add
    WidthArr: array[1..100] of integer; //存放分辨率的宽度
    HeightArr: array[1..100] of integer;//存放分辨率的高度

  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.TrackBar1Change(Sender: TObject);
var
        level: integer;
        hint : string;
begin
        level := TrackBar1.Position;
        case level of
                0: hint := '640X480像素';
                1: hint := '800X600像素';
                2: hint := '1024X768像素';
                3: hint := '1152X864像素';
                4: hint := '1280X1024像素';
        end;
        Label3.Caption := hint;
end;

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

procedure TForm1.FormCreate(Sender: TObject);

begin
        iModeNum := 4;
        TrackBar1.Min := 0;
        TrackBar1.Max := iModeNum;
        Label3.Caption := '640X480像素';
        TrackBar1.Position := 0;
end;


procedure TForm1.Button1Click(Sender: TObject);
var
        mDevMode: DEVMODE;
        position: integer;
begin
        position:= TrackBar1.Position;
        if EnumDisplaySettings(nil,position,mDevMode)<> False then
        begin
                with mDevMode do
                begin
                        case position of
                        0: begin
                             dmPelsWidth := 640;
                             dmPelsHeight := 480;
                           end;
                        1: begin
                            dmPelsWidth := 800;
                            dmPelsHeight := 600;
                          end;
                        2: begin
                            dmPelsWidth := 1024;
                            dmPelsHeight := 768;
                          end;
                        3: begin
                            dmPelsWidth := 1152;
                            dmPelsHeight := 864;
                          end;
                        4:begin
                            dmPelsWidth := 1280;
                            dmPelsHeight := 1024;
                          end;
                        end;
                        dmFields := DM_PELSWIDTH or DM_PELSHEIGHT;
                end;
                ChangeDisplaySettings(mDevMode, 0);
        end;
end;

end.