I don't manage to use the pointers with the DLLs

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Mod

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Joined: 8th Oct 2005

Location: France

Posted: 23rd Jun 2006 14:43

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In one of my codes which uses User32APIs, I need to transmit more
than 9 parameters to the DLL, what is apparently feasible with the
memblocks and the types of datas.

I started to test on a simple function of the DLL, ShowWindow,
which contains only two parameters, but, that doesn't work.

` set in window mode using DBpro
   set window on

` load the dll
   global user32 = 1
   load dll "user32",user32

` define constants usable with user32 ShowWindow command
  #constant SW_HIDE = 0
  #constant SW_NORMAL = 1
  #constant SW_MAXIMIZE = 3
  #constant SW_MINIMIZE = 6
  #constant SW_RESTORE = 9
  #constant SW_SHOW = 5
  #constant SW_SHOWDEFAULT = 10
  #constant SW_SHOWMAXIMIZED = 3
  #constant SW_SHOWMINIMIZED = 2
  #constant SW_SHOWMINNOACTIVE = 7
  #constant SW_SHOWNA = 8
  #constant SW_SHOWNOACTIVATE = 4
  #constant SW_SHOWNORMAL = 1

` get the active window handle
   hWnd = call dll(user32,"GetActiveWindow")

` create the memblock and fill it with datas
` dword = 4 bytes
   make memblock 1,8
   write memblock dword 1,0,hWnd
   write memblock dword 1,4,SW_MAXIMIZE

` create a type for the dll declaration and create a var
   type ShowWindow
      hWnd as dword
      nCmdShow as dword
   endtype

maximize as ShowWindow
   maximize.hWnd = hWnd
   maximize.nCmdShow = SW_MAXIMIZE

` call the function
` declaration = hWnd As Long, nCmdShow as long
   result = call dll(user32,"ShowWindow",hWnd,SW_MAXIMIZE) ` this line work without problem
   result = call dll(user32,"ShowWindow",get memblock ptr(1)) ` this doesn't work
   result = call dll(user32,"ShowWindow",maximize) ` idem :  doesn't work

` display the result of the dll command, and some info
   print "Handle = ",hWnd
   print "Pointer = ",*maximize," , ",maximize
   print "Result = ",result

` wait then end
   wait key

+ Code Snippet

` set in window mode using DBpro
   set window on

` load the dll
   global user32 = 1
   load dll "user32",user32

` define constants usable with user32 ShowWindow command
  #constant SW_HIDE = 0
  #constant SW_NORMAL = 1
  #constant SW_MAXIMIZE = 3
  #constant SW_MINIMIZE = 6
  #constant SW_RESTORE = 9
  #constant SW_SHOW = 5
  #constant SW_SHOWDEFAULT = 10
  #constant SW_SHOWMAXIMIZED = 3
  #constant SW_SHOWMINIMIZED = 2
  #constant SW_SHOWMINNOACTIVE = 7
  #constant SW_SHOWNA = 8
  #constant SW_SHOWNOACTIVATE = 4
  #constant SW_SHOWNORMAL = 1

` get the active window handle
   hWnd = call dll(user32,"GetActiveWindow")

` create the memblock and fill it with datas
` dword = 4 bytes
   make memblock 1,8
   write memblock dword 1,0,hWnd
   write memblock dword 1,4,SW_MAXIMIZE

` create a type for the dll declaration and create a var
   type ShowWindow
      hWnd as dword
      nCmdShow as dword
   endtype

   maximize as ShowWindow
   maximize.hWnd = hWnd
   maximize.nCmdShow = SW_MAXIMIZE

` call the function
` declaration = hWnd As Long, nCmdShow as long
   result = call dll(user32,"ShowWindow",hWnd,SW_MAXIMIZE) ` this line work without problem
   result = call dll(user32,"ShowWindow",get memblock ptr(1)) ` this doesn't work
   result = call dll(user32,"ShowWindow",maximize) ` idem :  doesn't work

` display the result of the dll command, and some info
   print "Handle = ",hWnd
   print "Pointer = ",*maximize," , ",maximize
   print "Result = ",result

` wait then end
   wait key

Can somebody say me what's wrong with my code, please ?

RPG Engine and Odyssée : http://modsoftware.ifrance.com

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IanM

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Joined: 11th Sep 2002

Location: In my moon base

Posted: 23rd Jun 2006 23:47

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The first line works as I expected.

The second line doesn't - also as I expected. The DLL is expecting two parameters, not one, and doesn't know that the value you are passing is a pointer to the values you want it to use.

The third line I wasn't sure about. Lee did add the ability to pass a typed variable to CALL DLL in the past, but I've never used it or seen it working. Your code is what I would expect to see though.

Maybe you should raise it as a bug in the DBPro bug forum.

For free Plug-ins and source code http://www.matrix1.demon.co.uk

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Mod

19

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Joined: 8th Oct 2005

Location: France

Posted: 24th Jun 2006 10:11

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I've understood something...I haven't used the good call dll function...

With call dll x(), the command works when I use memblocks, but there is still a problem with types :

` set in window mode using DBpro
   set window on

` load the dll
   global user32 = 1
   load dll "user32",user32

` define constants usable with user32 ShowWindow command
  #constant SW_HIDE = 0
  #constant SW_NORMAL = 1
  #constant SW_MAXIMIZE = 3
  #constant SW_MINIMIZE = 6
  #constant SW_RESTORE = 9
  #constant SW_SHOW = 5
  #constant SW_SHOWDEFAULT = 10
  #constant SW_SHOWMAXIMIZED = 3
  #constant SW_SHOWMINIMIZED = 2
  #constant SW_SHOWMINNOACTIVE = 7
  #constant SW_SHOWNA = 8
  #constant SW_SHOWNOACTIVATE = 4
  #constant SW_SHOWNORMAL = 1

` get the active window handle
   hWnd = call dll(user32,"GetActiveWindow")

` create the memblock and fill it with datas
` dword = 4 bytes
   make memblock 1,8
   write memblock dword 1,0,hWnd
   write memblock dword 1,4,SW_MAXIMIZE

` create a type for the dll declaration and create a var
   type ShowWindow
      hWnd as dword
      nCmdShow as dword
   endtype

maximize as ShowWindow
   maximize.hWnd = hWnd
   maximize.nCmdShow = SW_MAXIMIZE

` call the function
` declaration = hWnd As Long, nCmdShow as long
`   result = call dll(user32,"ShowWindow",hWnd,SW_MAXIMIZE) ` this line work without problem
   result = call dll x(user32,"ShowWindow",get memblock ptr(1),2) ` this works now
`   result = call dll x(user32,"ShowWindow",maximize,2) ` idem :  doesn't work

` display the result of the dll command, and some info
   print "Handle = ",hWnd
   print "Pointer = ",*maximize," , ",maximize
   print "Result = ",result

` wait then end
   wait key

+ Code Snippet

` set in window mode using DBpro
   set window on

` load the dll
   global user32 = 1
   load dll "user32",user32

` define constants usable with user32 ShowWindow command
  #constant SW_HIDE = 0
  #constant SW_NORMAL = 1
  #constant SW_MAXIMIZE = 3
  #constant SW_MINIMIZE = 6
  #constant SW_RESTORE = 9
  #constant SW_SHOW = 5
  #constant SW_SHOWDEFAULT = 10
  #constant SW_SHOWMAXIMIZED = 3
  #constant SW_SHOWMINIMIZED = 2
  #constant SW_SHOWMINNOACTIVE = 7
  #constant SW_SHOWNA = 8
  #constant SW_SHOWNOACTIVATE = 4
  #constant SW_SHOWNORMAL = 1

` get the active window handle
   hWnd = call dll(user32,"GetActiveWindow")

` create the memblock and fill it with datas
` dword = 4 bytes
   make memblock 1,8
   write memblock dword 1,0,hWnd
   write memblock dword 1,4,SW_MAXIMIZE

` create a type for the dll declaration and create a var
   type ShowWindow
      hWnd as dword
      nCmdShow as dword
   endtype

   maximize as ShowWindow
   maximize.hWnd = hWnd
   maximize.nCmdShow = SW_MAXIMIZE

` call the function
` declaration = hWnd As Long, nCmdShow as long
`   result = call dll(user32,"ShowWindow",hWnd,SW_MAXIMIZE) ` this line work without problem
   result = call dll x(user32,"ShowWindow",get memblock ptr(1),2) ` this works now
`   result = call dll x(user32,"ShowWindow",maximize,2) ` idem :  doesn't work

` display the result of the dll command, and some info
   print "Handle = ",hWnd
   print "Pointer = ",*maximize," , ",maximize
   print "Result = ",result

` wait then end
   wait key

RPG Engine and Odyssée : http://modsoftware.ifrance.com

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