Hi *,

I need help with OCX component (not visual I guess), which I need use in Lazarus application (to control another application, which supplies this OCX control).
I have imported type library using importtl.exe (new unit was created successfully)

Then in program I have created instance:
   v := CreateOleObject('SCAPS.ScSamlightClientCtrl');
or
   intf := CreateComObject(CLASS_ScSamlightClientCtrl) as
_DSamlight_client_ctrl_ocx;

But all next attampts using any interface method fail with EOleSysError "Catastrophic failure" (ErrorCode=-2147418113)

In Delphi it works, but only when I use TOLEControl descendant created by Delphi's import of ActiveX (into _TLB unit)
In Delphi I have :

TScSamlightClientCtrl = class(TOleControl)
...

but in Lazarus I have no equivalent? (When I Delphi I do same as in Lazarus I get same error also in Delphi)

I do not know exacly what to ask here ?
What is purpose of TOleControl and what TOleControl did more than I can do in Lazarus ?
Can I somehow workaround it in Lazarus ?

In short what I have imported from type lib in Lazarus is interface: _DSamlight_client_ctrl_ocx = dispinterface
['{05D31AA6-1306-4DA0-9AE2-A8771FF6FA94}']

    function ScIsRunning:Integer;dispid 1;
   ... etc.

end;

and CoClass:
   Class Function CoScSamlightClientCtrl.Create: _DSamlight_client_ctrl_ocx;
   begin
     Result := CreateComObject(CLASS_ScSamlightClientCtrl) as
_DSamlight_client_ctrl_ocx;
   end;

I can create instance calling CoScSamlightClientCtrl.Create, but as I wrote I can not use any method ...

Can somebody give any help ?

Thanks

-Laco.

What is the type of your V or intf variable?
I am wild guessing maybe they are not proper referenced type so the object is created and then immediately freed.

I would try
   v : OLEVariant;
or V :  _DSamlight_client_ctrl_ocx;

Dennis

V: OLEVariant;
intf: _DSamlight_client_ctrl_ocx;

I am wild guessing maybe they are not proper referenced type so the object is created and then immediately freed.

There is something strange behind scene. I have tried various methods:

var
   v1: OLEVariant;
   v2: ScSamlightClientCtrl;
   v: variant;
   ax: TActiveXContainer;
   disp: IDispatch;
   i: integer;
begin
   v1 := CreateOLEObject('SCAPS.ScSamlightClientCtrl');
   i := v1.scIsRunning;  // exception here
   v2 := CoScSamlightClientCtrl.Create;
   i := v2.scIsRunning;  // exception here
   ax := TActiveXContainer.Create(Self);
   //ax.OleClassName := 'SCAPS.ScSamlightClientCtrl';
   CoCreateInstance(CLASS_ScSamlightClientCtrl, nil,
CLSCTX_INPROC_SERVER or CLSCTX_LOCAL_SERVER, IDispatch, disp);
   ax.ComServer:=disp;
   ax.Active := True;
   v := disp;
   i := v.scIsRunning;  // exception here

So in every case it returns exception when I try call first time interface method ...
I am not familiar with ActiveX technology so I have no idea what is wrong ?

-Laco.

I remember in Delphi, I sometimes have to call CoInitialize and CoUninitialize.
Not sure if FPC has to do the same.
Have you tried that?

Dennis

I did debuging in Delphi looking at what is called and I have found,
that when I add two other lines it works!:
var
   Unknown: IUnknown;
   PersistStreamInit: IPersistStreamInit;
begin
   Unknown := CreateComObject(CLASS_ScSamlightClientCtrl);
   // these two lines are necessary:
   OleCheck(Unknown.QueryInterface(IPersistStreamInit, PersistStreamInit));
   OleCheck(PersistStreamInit.InitNew);
   FSamlightClientCtrl := Unknown as ScSamlightClientCtrl;
  ...
end;

I have no idea why they are needed, but may be that they perform some initialization of component ... I also wonder if other users can suffer from it ?

-Laco.

En Wed, 19 Oct 2016 11:07:35 -0500, Dennis via Lazarus