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==== SendMessage working with ListBox (OpenInsight 32-bit Specific) ====
=== At 24 FEB 2004 04:37:49PM Kevin Bolitho wrote: ===
 
{{tag>"OpenInsight 32-bit Specific"}}
 
<QUOTE>
I am trying to determine the row height of a listbox



I see in the Borland Windows.H file "#define LB_GETITEMHEIGHT       (WM_USER+34)" 



This is what I am trying to do...



hWnd=Get_Property(BubCtrl,"HANDLE")

RowHeight=SendMessage(hWnd,1058,1,0)	;* 1058=1024 + 34





Result is

hWnd is returned with a number that looks resonable.

RowHeight is always returned as 0 rather than the number of pixels. 



If anyone else has done this then my error may be obvious.



Thanks for responses in advance.




</QUOTE>
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=== At 24 FEB 2004 07:38PM [url=http://www.sprezzatura.com]The Sprezzatura Group[/url] wrote:  ===

<QUOTE>Kevin,



Was that a 16 bit windows.h file perchance?



The Win32 header files state: 



#define LB_GETITEMHEIGHT 0x01A1



Which returns the correct value when used with SendMessage on my OI system.  Basically MS changed a lot of message IDs in Win32 so make sure you have the correct headers...



[url=http://www.sprezzatura.com]The Sprezzatura Group[/url]

[i]World leaders in all things RevSoft[/i]

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</QUOTE>

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=== At 24 FEB 2004 11:00PM Pat McNerthney wrote:  ===

<QUOTE>Kevin,



The documentation on [url=http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/commctls/listboxes/listboxreference/listboxmessages/lb_getitemheight.asp]here[/url] on LB_GETITEMHEIGHT says the following about the wParam parameter (the third parameter of SendMessage):



"Specifies the zero-based index of the list box item. This index is used only if the list box has the LBS_OWNERDRAWVARIABLE style; otherwise, it must be zero."



Your code is passing one in this parameter.



Pat

</QUOTE>


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