Get the Processor Usage

Problem/Question/Abstract:

How to get the processor usage

Answer:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ComCtrls, CommCtrl, StdCtrls, Menus, WinSpool, ExtCtrls, Buttons, Registry;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Timer1: TTimer;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
    started: boolean;
    reg: TRegistry;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
  Dummy: array[0..1024] of byte;
begin
  // Stats started by Button1 hit
  Reg := TRegistry.Create;
  Reg.RootKey := HKEY_DYN_DATA; // Statistic data is saved under this topic
  { Before starting retrieving statistic data you have to query
    the appropiate key under 'PerfStats\StartStat'. }
  Reg.OpenKey('PerfStats\StartStat', false);
    // Open this key first to start collecting performance data
  Reg.ReadBinaryData('KERNEL\CPUUsage', Dummy, Sizeof(Dummy));
  Reg.CloseKey;
  started := true;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
  CPUU: integer;
begin
  { After starting the collection of statistic data, you can retrieve the
    recent value under the 'PerfStats\StatData' key. This is done by a timer
    event in this example }
  if started then
  begin
    Reg.OpenKey('PerfStats\StatData', false); // Open extension kex for txt files
    Reg.ReadBinaryData('KERNEL\CPUUsage', CPUU, SizeOf(Integer));
    Reg.CloseKey;
    Label1.Caption := IntToStr(CPUU) + '%';
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  Dummy: array[0..1024] of byte;
begin
  // Button2 hit stops statistic collection
  { Collecting statistic data is stopped by a query under 'PerfStats/StopStat' }
  Reg.OpenKey('PerfStats\StopStat', false);
    // Open this key first to start collecting performance data
  Reg.ReadBinaryData('KERNEL\CPUUsage', Dummy, SizeOf(Dummy));
  Reg.Free;
  Started := false;
end;

end.