unitfrmmain.pas

里面包含有101种简易的Delphi源码

unit unitFrmMain;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  AppEvnts;

type
  TForm1 = class(TForm)
    ApplicationEvents1: TApplicationEvents;
    procedure ApplicationEvents1Idle(Sender: TObject; var Done: Boolean);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
//声明响应WM_HOTKEY消息的方法
    procedure WMHotKey(var Msg: TWMHotKey); message WM_HOTKEY;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
const id_SnapShot = 115; //定义热键标识符


{$R *.DFM}

procedure TForm1.ApplicationEvents1Idle(Sender: TObject;
  var Done: Boolean);
begin
  if GetAsyncKeyState(VK_SNAPSHOT) <> 0 then
    Form1.Caption := '已经按下PrintScreen键';
  Done := True;
end;

procedure TForm1.WMHotKey(var Msg: TWMHotKey);
begin
  if Msg.HotKey = id_SnapShot then
    ShowMessage('已经按下PrintScreen键');
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  RegisterHotKey(Form1.Handle, id_SnapShot, 0, VK_SNAPSHOT); //定义热键
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  UnRegisterHotKey(Form1.Handle, id_SnapShot); //释放已经登记的热键
end;

end.