TScreen 类 - 判断当前焦点在哪个窗体上

unit Unit1;

interface

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

type
TForm1 = class(TForm)
Timer1: TTimer;
Button1: TButton;
procedure Timer1Timer(Sender: TObject);
procedure Button1Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses Unit2; {本例还包含另一个窗体 Form2}

//标题显示当前窗体的类名
procedure TForm1.Timer1Timer(Sender: TObject);
begin
Text := Screen.ActiveForm.ClassName;
end;

//激活另一个窗体一试
procedure TForm1.Button1Click(Sender: TObject);
begin
Form2.Show;
end;

end.