All,
I'm writing a TurboVision App to cross compile to Linux - but debugging on my main Win32 box.

In this app; I'm attempting to use the TFPTimer component to trigger an event every 1000ms. I can't get the bugger to compile; despite google searches and a lot of experience in Delphi.

The compiler always seems to throw an error simular to:

TVBOOT.PAS(52,20) Error: Incompatible types: got "<procedure variable type of   procedure(TObject) of object;Register>" expected "CLASSES.<procedure variable type of procedure(TObject) of object;Register>"

I began by using the advice of Graeme in the post: http://readlist.com/lists/lists.freepascal.org/fpc-pascal/0/3897.html

I know this is simple compiler gymnastics; but I just can't seem to figure it out. John

uses
CRT,App,Objects,Menus,Drivers,Views,Dialogs,
fpTimer;

type
 TBootApp = object(TApplication)
 private
  aTimer : TfpTimer;
 protected
  constructor Init;
  destructor Done; virtual;
  procedure InitStatusLine; virtual;
  procedure HandleEvent(var Event: TEvent); virtual;
  procedure Idle; virtual;
  function NewDialog : word;
 public
  procedure TimerTimer( Sender : TObject );
 end;
 PDemoDialog = ^TDemoDialog;
 TDemoDialog = object(TDialog)
 end;
var
 BootApp : TBootApp;
 Dialog  : PDemoDialog;
 DoDialog : Boolean;
constructor TBootApp.Init;
BEGIN
 aTimer := TFPTimer.Create(nil);
 aTimer.Interval := 500; //ms
 aTimer.Enabled := False;
 aTimer.OnTimer := @TimerTimer;   //compiler barfs <<<---- here!
END;
destructor TBootApp.Done;
BEGIN
 ATimer.Free;
END;
procedure TBootApp.TimerTimer( Sender : TObject );
BEGIN
END;

You are mixing a Delphi Class (TFPTimer) and a TV object (Tapplication). You can never mix them. You can use them independent of each other in the same application, but not assign a tp-style method to a delphi-style event handler.

You need to use a Delphi class TApplication object. If that is not possible, what you can do is create a go-between class:

TMyEvent = Class(TObject)
   Procedure MyEventHandler( Sender : TObject );
   MyApplication : TApplication
end;
Procedure TMyEvent.MyEventHandler(Sender : TObject );
begin
  MyApplication.TimerTimer(Sender);
end;

And assign this to the timer event:

  constructor TBootApp.Init;
  BEGIN
   FmyHandler:=TMyEvent.create;
   FMyhandler.MyApplication:=Self;
   aTimer := TFPTimer.Create(nil);
   aTimer.Interval := 500; //ms
   aTimer.Enabled := False;
   aTimer.OnTimer := @FMyHandler.MyEventHandler;
  END;

Michael.

In our previous episode, Zitt Zitterkopf said:

My guess is that you try to assign a methodvar of the TP object type to a variable from the Delphi class type.

Since a methodvar contains a reference to the object, there is a typemismatch for that.