HTML Help Problem

[Dean Schrage]

Question, I have both a parent dialog and a DLL called from the parent. If I open a CHM file using the following code, and then open a different help file from the DLL (different file but same call encapsulated in the DLL), the application hangs. Can anyone suggest why this is or a remediation?

thanks

regards

Dean

   '  Derived from:     http://www.powerbasic.com/support/forums/Forum4/HTML/002083.html
   '  see also:         http://www.powerbasic.com/support/forums/Forum7/HTML/000314.html

   'Include HtmlHelp.inc file to setup HtmlHelp equates like %HH_HELP_CONTEXT
   #INCLUDE "htmlhelp.inc"       '  provided as part of PB

   DECLARE FUNCTION HtmlHelp LIB "hhctrl.ocx" ALIAS "HtmlHelpA" ( BYVAL hwndCaller  AS DWORD    , _
                                                                        pszFile     AS ASCIIZ   , _
                                                                  BYVAL uCommand    AS LONG     , _
                                                                  BYVAL dwData      AS LONG        ) AS LONG

   DECLARE FUNCTION HtmlHelp_ByKeyword(hDlg                   AS LONG     , _
                                       S_FileName_HtmlHelp    AS STRING   , _
                                       S_HTMLHelp_Keyword     AS STRING      ) AS LONG

FUNCTION HtmlHelp_ByKeyword(hDlg                   AS LONG     , _
                            S_FileName_HtmlHelp    AS STRING   , _
                            S_HTMLHelp_Keyword     AS STRING      ) AS LONG

   '  Generate STRPTR from keyword
   '  Derived from  http://www.powerbasic.com/support/forums/Forum7/HTML/000314.html
   '  General usage is as follows:
   '  HtmlHelp_ByKeyword CBHNDL, S_FilePath_FTEAgent + "FTEAgent.chm" , "Activating the Agent"


   DIM A_FileName_HtmlHelp    AS ASCIIZ*255
   DIM A_HTMLHelp_Keyword     AS ASCIIZ*255
   DIM hlk                    AS HH_AKLINK

   A_HTMLHelp_Keyword   = S_HTMLHelp_Keyword
   hlk.cbStruct         = SIZEOF(hlk)
   hlk.fReserved        = %FALSE
   hlk.pszKeywords      = VARPTR(A_HTMLHelp_Keyword)
   hlk.pszUrl           = %NULL
   hlk.pszMsgText       = %NULL
   hlk.pszMsgTitle      = %NULL
   hlk.pszWindow        = %NULL
   hlk.fIndexOnFail     = %TRUE

   A_FileName_HtmlHelp  = S_FileName_HtmlHelp

   HtmlHelp hDlg, A_FileName_HtmlHelp, %HH_KEYWORD_LOOKUP   , BYREF hlk

END FUNCTION


#IF 00   '  Usage example
   HtmlHelp CBHNDL, A_FileName_Help_CHM, 00              , 00  '  to display the default listing
   HtmlHelp CBHNDL, A_FileName_Help_CHM, %HH_HELP_CONTEXT, 10  '  to display unit number 10


   '  keywork pointer type, just for reference, resides in the htmlhelp.inc file
   TYPE HH_AKLINK
      cbStruct     AS LONG
      fReserved    AS LONG
      pszKeywords  AS ASCIIZ PTR
      pszUrl       AS ASCIIZ PTR
      pszMsgText   AS ASCIIZ PTR
      pszMsgTitle  AS ASCIIZ PTR
      pszWindow    AS ASCIIZ PTR
      fIndexOnFail AS LONG
   END TYPE

         '  Call by strptr keyword
         DIM A_HTMLHelp_Keyword     AS ASCIIZ*255
         DIM hlk                    AS HH_AKLINK
         A_HTMLHelp_Keyword = "About FTE"
         hlk.cbStruct      = SIZEOF(hlk)
         hlk.fReserved     = %FALSE
         hlk.pszKeywords   = VARPTR(A_HTMLHelp_Keyword)
         hlk.pszUrl        = %NULL
         hlk.pszMsgText    = %NULL
         hlk.pszMsgTitle   = %NULL
         hlk.pszWindow     = %NULL
         hlk.fIndexOnFail  = %TRUE
         A_FileName_FTEAgentHelp    = S_FilePath_FTEAgent + "Help FTE Agent.chm"
         HtmlHelp CBHNDL, A_FileName_FTEAgentHelp, %HH_KEYWORD_LOOKUP, BYREF hlk


   '  Also taken from the htmlhelp.inc file:
   ' Commands to pass to HtmlHelp()

%HH_DISPLAY_TOPIC        = &H0000
%HH_HELP_FINDER          = &H0000   ' WinHelp equivalent
%HH_DISPLAY_TOC          = &H0001
%HH_DISPLAY_INDEX        = &H0002
%HH_DISPLAY_SEARCH       = &H0003
%HH_SET_WIN_TYPE         = &H0004
%HH_GET_WIN_TYPE         = &H0005
%HH_GET_WIN_HANDLE       = &H0006
%HH_ENUM_INFO_TYPE       = &H0007   ' Get Info type name, call repeatedly to enumerate, -1 at end
%HH_SET_INFO_TYPE        = &H0008   ' Add Info type to filter.
%HH_SYNC                 = &H0009
%HH_RESERVED1            = &H000A
%HH_RESERVED2            = &H000B
%HH_RESERVED3            = &H000C
%HH_KEYWORD_LOOKUP       = &H000D
%HH_DISPLAY_TEXT_POPUP   = &H000E   ' display string resource id or text in a popup window
%HH_HELP_CONTEXT         = &H000F   ' display mapped numeric value in dwData
%HH_TP_HELP_CONTEXTMENU  = &H0010   ' text popup help, same as WinHelp %HELP_CONTEXTMENU
%HH_TP_HELP_WM_HELP      = &H0011   ' text popup help, same as WinHelp %HELP_WM_HELP
%HH_CLOSE_ALL            = &H0012   ' close all windows opened directly or indirectly by the caller
%HH_ALINK_LOOKUP         = &H0013   ' ALink version of %HH_KEYWORD_LOOKUP
%HH_GET_LAST_ERROR       = &H0014   ' not currently implemented ' See HHERROR.h [*** PB note: the Windows SDK has no such file]
%HH_ENUM_CATEGORY        = &H0015   ' Get category name, call repeatedly to enumerate, -1 at end
%HH_ENUM_CATEGORY_IT     = &H0016   ' Get category info type members, call repeatedly to enumerate, -1 at end
%HH_RESET_IT_FILTER      = &H0017   ' Clear the info type filter of all info types.
%HH_SET_INCLUSIVE_FILTER = &H0018   ' set inclusive filtering method for untyped topics to be included in display
%HH_SET_EXCLUSIVE_FILTER = &H0019   ' set exclusive filtering method for untyped topics to be excluded from display
%HH_INITIALIZE           = &H001C   ' Initializes the help system.
%HH_UNINITIALIZE         = &H001D   ' Uninitializes the help system.
%HH_SET_QUERYSERVICE     = &H001E   ' Set the Host IQueryService interface
%HH_PRETRANSLATEMESSAGE  = &H00fd   ' Pumps messages. (%NULL, %NULL, MSG PTR).
%HH_SET_GLOBAL_PROPERTY  = &H00fc   ' Set a global property. (%NULL, %NULL, HH_GPROP)


#ENDIF

[Michael Mattias]

>HtmlHelp hDlg, A_FileName_HtmlHelp, %HH_KEYWORD_LOOKUP , BYREF hlk

HH_KEYWORD_LOOKUP
....

You must first call the HH_DISPLAY_TOPIC command before calling this command to ensure that the help window is created.

Required call not shown. Doesn't mean you don't do that, but I don't see it here.

PS: That one or more functions happen to be loaded from a DLL is immaterial.

[Dean Schrage]

thanks, I will test later and followup this posting.

[Dean Schrage]

I tried the HH_DISPLAY_TOPIC command first, basically leading the call for TOC or a help topic. It still hangs. Any ideas?

[Michael Mattias]

"hang" is an insufficient description of the problem. It is only marginally better than the allegedly-failing code you have posted.

Does the call to HTML help return? If so, what is the error code and what does it mean?

No... wait a minute... FIRST... run the application MINUS any calls to HTMLHelp. If that does not "hang" then you know the problem is with the way you've implemented HTMLHelp. Right know for all we know you are in a 'DO UNTIL 2+2 <> 4 ' loop.

MCM