Personally I don't like using BPL's and prefer dll's. While Objects cannot be transported between dll's interfaces are very happy and I have had reasonable success in the past using activex forms from dll's and docking them into the appropriate position of the main application.
Just a thought. -----Original Message----- From: Phil Middlemiss [mailto:[EMAIL PROTECTED] Sent: Monday, 17 March 2003 9:24 a.m. To: Multiple recipients of list delphi Subject: Re: [DUG]: Passing Objects from DLLs Thanks Myles, Looks like we need to do a little bit of re-design. Phil. ----- Original Message ----- From: "Myles Penlington" <[EMAIL PROTECTED]> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]> Sent: Monday, March 17, 2003 8:50 AM Subject: RE: [DUG]: Passing Objects from DLLs > That is why use BPL's instead. With a DLL you have your own copy of System > and hence TObject and then get the case that TObject is <> to TObject as > there is now two copies TObject VMT's etc. > > I seem to remember there are other issues with DLL's vs BPLs too. > > Myles. > > > > -----Original Message----- > From: Phil Middlemiss [mailto:[EMAIL PROTECTED] > Sent: Monday, 17 March 2003 8:17 a.m. > To: Multiple recipients of list delphi > Subject: [DUG]: Passing Objects from DLLs > > > Hi all, > > we are building a plugin architecture and have a few questions about passing > objects from a DLL into the main app. > > For example, we want a dll to be able to pass an instance of a TPanel that > is then embedded into a TNotebook on a form in the main application. We pass > this panel, as a pointer, as part of a variant open array parameter (array > of const). So the DLL would call something like: > > MyNewPanel := TPanel.Create(nil); // we will free it our selves later > MyNewPanel.Parent := nil; // the main app will assign the parent > PluginManager.ProcessCommand("AddPanel", [EMAIL PROTECTED]); > > This is effectively received in the main app as: > > TMainApp.ProcessCommand(CommandName : WideString; Parameters : Array of > Const); > var ANewPanel : TPanel; > begin > ... > ANewPanel := TPanel(Parameters[0].vPointer^); > ... > end; > > The panel seems to be received correctly - sort of. The Evaluate/Modify > window evaluates ANewPanel.Classtype as TClass($12345) except with the > actual address. If we now try and assign a font to the panel we get an error > "Can't assign a TFont to a TFont". > > It seems that the RTTI is not correctly being passed from the DLL to the > main app. Is this a side effect of passing objects from a DLL, or is this a > side effect of passing it in a variant open array? How do we get around > this? > > Phil. > > -------------------------------------------------------------------------- - > New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > -------------------------------------------------------------------------- - > New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
