N长时间没有操作鼠标键盘，自动关闭显示器、锁屏

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
  Vcl.ExtCtrls, Vcl.StdCtrls, Vcl.ComCtrls;

type
  LASTINPUTINFO = record
    cbSize: UINT;
    dwTime: DWORD;
  end;

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    RichEdit1: TRichEdit;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
    FLastInputTime: DWORD;
    function GetLastInputTime: DWORD;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

function GetLastInputInfo(var plii: LASTINPUTINFO): BOOL; stdcall; external 'user32.dll';

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  lii: LASTINPUTINFO;
begin
  lii.cbSize := SizeOf(LASTINPUTINFO);

  Timer1.Interval := 1000; // 一分钟
  Timer1.Enabled := True;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  FLastInputTime := GetLastInputTime;
  if (GetTickCount - FLastInputTime) > 5000 then
  begin
//    RichEdit1.Lines.Add('power off');
    SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 2);
  end;
  if (GetTickCount - FLastInputTime) > 10000 then
  begin
//    RichEdit1.Lines.Add('lock station');
    LockWorkStation;
  end;
end;

function TForm1.GetLastInputTime: DWORD;
var
  lii: LASTINPUTINFO;
begin
  lii.cbSize := SizeOf(LASTINPUTINFO);
  if GetLastInputInfo(lii) then
    Result := lii.dwTime;
end;

end.