unit Unit3;

interface

uses
  Classes, SysUtils, Graphics, ExtCtrls;

type
  Tthread3 = class(TThread)
  private
    tt: TShape;
    f: boolean;
    { Private declarations }
  protected
    procedure Execute; override;
  public
    constructor Create(flag: Boolean; lamp: TShape; Ctrl: Boolean); overload;

  end;

implementation
uses main;
{ Tthread3 }

constructor Tthread3.Create(flag: Boolean; lamp: TShape; Ctrl: Boolean);
begin
  tt := lamp;
  f := Ctrl;
  Create(flag);
end;

{控制交通燈}

procedure Tthread3.Execute;
var
  i: integer;
begin
  for i := 1 to 5000 do
  begin
    if f = true then
    begin
      tt.Brush.Color := clRed;
      f := false;
    end
    else if f = false then
    begin
      tt.Brush.Color := clLime;
      f := true;
    end;
    sleep(5000);
  end;
  { Place thread code here }

end;

end.