Ohhh no - you try to call the API with a window handle as a parameter, but the the API is defined like the following:

BOOL PrintDlg( LPPRINTDLG lppd // initialization data );

So you have to call it with the address of a PRINTDLG structure. This structure contains informations used to initialize the dialog box (including the handle to the owner window).

See http://www.msdn.microsoft.com/library/default.asp?URL=/library/psdk/winui/co mmdlg3_7xwy.htm

How to do it in Squeak: - create a new subclass Win32PRINTDLG of ExternalStructure - implement the class method #fields to define the fields of the struct like: Win32PRINTDLG(class)>>fields "Win32PRINTDLG defineFields" ^#( #(#lStructSize 'long') #(#hwndOwner 'long') ... ) see http://www.msdn.microsoft.com/library/default.asp?URL=/library/psdk/winui/co mmdlg3_7xwy.htm for the structure definition (note that any structure member is a long (4 bytes), except nFromPage, nToPage, nMinPage, nMaxPage, nCopies (only two bytes) - evaluate "Win32PRINTDLG defineFields" to create accessor methods on the instance side - create an API call method shellPrintDialog: aWin32PRINTDLG "Displays a print dialog box" <apicall: bool 'PrintDlgA' (Win32PRINTDLG*) module: 'comdlg32.dll'> ^self externalCallFailed This should work. If the API call goes wrong it returns FALSE (= 0).

I personally dont like the way Squeak calls API functions. In Smalltalk MT you only write: WINAPI PrintDlg: PRINTDLG new

That's a little bit easier ;)

Hope this helps Torsten

BTW: It's interesting that you mail address is Kronos.com - my nickname is Cronos

-----Original Message----- From: Norton, Chris [mailto:chrisn@Kronos.com] Sent: Freitag, 30. Juni 2000 04:26 To: Squeak (E-mail) Subject: [Q] Using FFI to call standard Windows dialogs

Hi Folks.

I was experimenting with FFI on my Windows NT box and I kept crashing my image (virtual memory dumps). Can anybody help me with this call?

~~~~~~~~~~~~~~~~~~~~~~~~~~ Win32Shell>> shellPrintDialog: aHWND "Win32Shell new shellPrintDialog: Win32Window getFocus"

<apicall: bool 'PrintDlgA' (Win32Window) module: 'comdlg32.dll'> ^self externalCallFailed

~~~~~~~~~~~~~~~~~~~~~~~~~~

I'm trying to launch the print dialog.

Thanks for your thoughts!

---==> Chris

PS> And my next question is, of course, how do I get a document to print once I've got the dialog launching from Squeak (e.g. how do I provide the dialog with a document to print?)...