Klasse soll Anwendung nur bei best. Änderung benachrichtigen

[DeddyH]

Hab mal in Notepad etwas editiert, daher ungetestet:

Delphi-Quellcode:

unit Testclass; 

interface 

uses 
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Forms, Dialogs, 
    StdCtrls, WinSock, ActiveX, ComObj, ExtCtrls; 

type 
    TOnChange_Proc = procedure() of object; 
    TMyClass = class(TObject) 

    private 
    FTimer              : TTimer; 
    FStatus, OldStatus  : Boolean; 
    FOnChange           : TOnChange_Proc; 

//    procedure OnChange; 
    function  getAvailable: Boolean; 
    procedure testTimer(Sender : TObject); 
    procedure setStatus(value: Boolean); 

    public 
    constructor Create; 
    destructor destroy; override; 
    property OnChange_Func : TOnChange_Proc read FOnChange write FOnChange; 
    property Status : Boolean read FStatus write setStatus; 
    property Timer : TTimer read FTimer write FTimer; 
end; 

implementation 

constructor TMyClass.Create; 
begin 
inherited; 
    FTimer := TTimer.Create(nil); 
    FTimer.enabled := false; 
    FTimer.Interval := 1000; 
    FTimer.OnTimer := testTimer; 
    FOnChange := nil;
    FStatus := true;
    OldStatus := true; 
end; 

destructor TMyClass.Destroy; 
begin 
    FTimer.Free; 
    inherited; 
end; 

{procedure TMyClass.OnChange; 
begin 
  if Assigned(FOnChange) then 
    FOnChange; 
end; }

procedure TMyClass.setStatus(value: Boolean); 
begin 
  FStatus := value; 
  if Assigned(FOnChange) then 
    FOnChange; 
end; 

procedure TMyClass.testTimer(Sender:TObject); 
begin 
    GetAvailable; 
//    onchange; 
end; 

function TMyClass.GetAvailable: Boolean; 
begin 
  if FStatus <> OldStatus then
    begin
      OldStatus := FStatus;
      if Assigned(FOnChange) then
        FOnChange;
    end;
end; 

end.