可以计算到<<毫秒级>>的控件_delphi教程

unit mwFastTime;

interface

uses
  SysUtils, Windows, Classes;

type
  TmwFastTime = class(TComponent)
  private
    c, n1, n2: TLargeInteger;
    function GetElapsedTime: ShortString;
    function GetElapsed: Extended;
  protected
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    Property Elapsed: Extended read GetElapsed;
    Property ElapsedTime: ShortString read GetElapsedTime;
    Procedure Start;
    Procedure Stop;
  published
    Property Name;
    Property Tag;
  end;

procedure Register;

implementation

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

procedure Register;
begin
  RegisterComponents(mw, [TmwFastTime]);
end;

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

constructor TmwFastTime.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  QueryPerformanceFrequency(c);
end;

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

destructor TmwFastTime.Destroy;
begin
  inherited Destroy;
end;

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

function TmwFastTime.GetElapsed: Extended;
begin
{$IFDEF VER120}
  Result:= (_LARGE_INTEGER(n2).QuadPart – _LARGE_INTEGER(n1).QuadPart) / _LARGE_INTEGER(c).QuadPart;
{$ELSE}
  Result:= (n2.QuadPart – n1.QuadPart) / c.QuadPart;
{$ENDIF}
end;

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

function TmwFastTime.GetElapsedTime: ShortString;
begin
{$IFDEF VER120}
  Result := format(Seconds: %g, [GetElapsed]);
{$ELSE}
  Result := format(Seconds: %g, [GetElapsed]);
{$ENDIF}
end;

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

Procedure TmwFastTime.Start;
begin
  QueryPerformanceCounter(n1);
end;

{~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~}

Procedure TmwFastTime.Stop;
begin
  QueryPerformanceCounter(n2);
end;

end.