git.saurik.com Git - wxWidgets.git/blame_incremental

... / ...

Commit	Line	Data
	1	<HTML>
	2
	3	<HEAD>
	4	<TITLE>wxWidgets 2 for Windows FAQ</TITLE>
	5	</HEAD>
	6
	7	<BODY BGCOLOR=#FFFFFF TEXT=#000000 VLINK="#00376A" LINK="#00529C" ALINK="#313063">
	8
	9	<font face="Arial, Lucida Sans, Helvetica">
	10
	11	<table width=100% border=0 cellpadding=3 cellspacing=0>
	12	<tr>
	13	<td bgcolor="#004080" align=left height=24 background="images/bluetitlegradient.gif">
	14	<font size=+1 face="Arial, Lucida Sans, Helvetica" color="#FFFFFF">
	15	<b>wxWidgets 2 for Windows FAQ</b>
	16	</font>
	17	</td>
	18	</tr>
	19	</table>
	20
	21	<P>
	22
	23	See also <a href="faq.htm">top-level FAQ page</a>.
	24	<hr>
	25	<h3>List of questions in this category</h3>
	26	<ul>
	27	<li><a href="#platforms">Which Windows platforms are supported?</a></li>
	28	<li><a href="#wince">What about Windows CE?</a></li>
	29	<li><a href="#winxp">What do I need to do for Windows XP?</a></li>
	30	<li><a href="#compilers">What compilers are supported?</a></li>
	31	<li><a href="#bestcompiler">Which is the best compiler to use with wxWidgets 2?</a></li>
	32	<li><a href="#unicode">Is Unicode supported?</a></li>
	33	<li><a href="#doublebyte">Does wxWidgets support double byte fonts (Chinese/Japanese/Korean etc.)?</a></li>
	34	<li><a href="#dll">Can you compile wxWidgets 2 as a DLL?</a></li>
	35	<li><a href="#exesize">How can I reduce executable size?</a></li>
	36	<li><a href="#mfc">Is wxWidgets compatible with MFC?</a></li>
	37	<li><a href="#setuph">Why do I get errors about setup.h not being found?</a></li>
	38	<li><a href="#asuffix">Why do I get errors about FooBarA when I only use FooBar in my program?</a></li>
	39	<li><a href="#newerrors">Why my code fails to compile with strange errors about new operator?</a></li>
	40	<li><a href="#mfcport">How do I port MFC applications to wxWidgets?</a></li>
	41	<li><a href="#crash">Why do I sometimes get bizarre crash problems using VC++ 5/6?</a></li>
	42	<li><a href="#makefiles">How are the wxWidgets makefiles edited under Windows?</a></li>
	43	<li><a href="#vcdebug">How do you use VC++'s memory leak checking instead of that in wxWidgets?</a></li>
	44	<li><a href="#shortcutproblem">Why are menu hotkeys or shortcuts not working in my application?</a></li>
	45	<li><a href="#regconfig">Why can I not write to the HKLM part of the registry with wxRegConfig?</a></li>
	46	<li><a href="#access">Is MS Active Accessibility supported?</a></li>
	47	<li><a href="#dspfmt">Why does Visual C++ complain about corrupted project files??</a></li>
	48	<li><a href="#crtmismatch">Visual C++ gives errors about multiply defined symbols, what can I do?</a></li>
	49	</ul>
	50	<hr>
	51
	52	<h3><a name="platforms">Which Windows platforms are supported?</a></h3>
	53
	54	wxWidgets 2 can be used to develop and deliver applications on Windows 3.1, Win32s,
	55	Windows 95, Windows 98, Windows NT, Windows 2000, and Windows XP. A Windows CE
	56	version is being looked into (see below).<P>
	57
	58	wxWidgets 2 is designed to make use of WIN32 features and controls. However, unlike Microsoft,
	59	we have not forgotten users of 16-bit Windows. Most features
	60	work under Windows 3.1, including wxTreeCtrl and wxListCtrl using the generic implementation.
	61	However, don't expect very Windows-95-specific classes to work, such as wxTaskBarIcon. The wxRegConfig
	62	class doesn't work either because the Windows 3.1 registry is very simplistic. Check out the 16-bit
	63	makefiles to see what other files have been left out.
	64	<P>
	65	16-bit compilation is supported under Visual C++ 1.5, and Borland BC++ 4 to 5.
	66	<P>
	67
	68	wxWidgets 2 for Windows will also compile on Unix with gcc using Wine from <a href="http://www.winehq.org" target=_top>WineHQ</a>.
	69	The resulting executables are Unix binaries that work with the Wine Windows API emulator.<P>
	70
	71	You can also compile wxWidgets 2 for Windows on Unix with Cygwin or Mingw32, resulting
	72	in executables that will run on Windows. So in theory you could write your applications
	73	using wxGTK or wxMotif, then check/debug your wxWidgets for Windows
	74	programs with Wine, and finally produce an ix86 Windows executable using Cygwin/Mingw32,
	75	without ever needing a copy of Microsoft Windows. See the Technical Note on the Web site detailing cross-compilation.<P>
	76
	77	<h3><a name="wince">What about Windows CE?</a></h3>
	78
	79	This port is largely complete. For further information, see the <a href="http://www.wxwidgets.org/embedded.htm#wxwince">wxEmbedded</a> page.<P>
	80
	81	<h3><a name="winxp">What do I need to do for Windows XP?</a></h3>
	82
	83	In the same directory as you have your executable (e.g. foo.exe) you
	84	put a file called foo.exe.manifest in which you have something like
	85	the following:
	86
	87	<pre>
	88	<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
	89	<assembly
	90	xmlns="urn:schemas-microsoft-com:asm.v1"
	91	manifestVersion="1.0">
	92	<assemblyIdentity
	93	processorArchitecture="x86"
	94	version="5.1.0.0"
	95	type="win32"
	96	name="foo.exe"/>
	97	<description>Foo program</description>
	98	<dependency>
	99	<dependentAssembly>
	100	<assemblyIdentity
	101	type="win32"
	102	name="Microsoft.Windows.Common-Controls"
	103	version="6.0.0.0"
	104	publicKeyToken="6595b64144ccf1df"
	105	language="*"
	106	processorArchitecture="x86"/>
	107	</dependentAssembly>
	108	</dependency>
	109	</assembly>
	110	</pre>
	111
	112	If you want to add it to your application permanently,
	113	you can also include it in your .rc file using this
	114	line:<P>
	115
	116	<PRE>
	117	1 24 "winxp.manifest"
	118	</PRE>
	119
	120	In wxWidgets 2.5, this will be in the wx/msw/wx.rc and
	121	so will happen automatically so long as you include wx.rc
	122	in your own .rc file.<P>
	123
	124	For an explanation of this syntax, please see
	125	<a href="http://delphi.about.com/library/bluc/text/uc111601a.htm" target=_new>this
	126	article</a>.
	127	<P>
	128
	129	<h3><a name="compilers">What compilers are supported?</a></h3>
	130
	131	Please see the wxWidgets 2 for Windows install.txt file for up-to-date information, but
	132	currently the following are known to work:<P>
	133
	134	<ul>
	135	<li>Visual C++ 1.5, 4.0, 5.0, 6.0, 7.0, 7.1
	136	<li>Borland C++ 4.5, 5.0, 5.5
	137	<li>Borland C++Builder 1.0, 3.0, X
	138	<li>Watcom C++ 10.6 (Win32), OpenWatcom 1.0
	139	<li>Cygwin (using configure)
	140	<li>Mingw32
	141	<li>MetroWerks CodeWarrior (many versions)
	142	<li>Digital Mars 8.34+
	143	</ul>
	144	<P>
	145
	146
	147	<h3><a name="bestcompiler">Which is the best compiler to use with wxWidgets 2?</a></h3>
	148
	149	It's partly a matter of taste, but I (JACS) prefer Visual C++ since the debugger is very
	150	good, it's very stable, the documentation is extensive, and it generates small executables.
	151	Since project files are plain text, it's easy for me to generate appropriate project files
	152	for wxWidgets samples.<P>
	153
	154	Borland C++ is fine - and very fast - but it's hard (impossible?) to use the debugger without using project files, and
	155	the debugger is nowhere near up to VC++'s quality. The IDE isn't great.<P>
	156
	157	C++Builder's power isn't really used with wxWidgets since it needs integration with its
	158	own class library (VCL). For wxWidgets, I've only used it with makefiles, in which case
	159	it's almost identical to BC++ 5.0 (the same makefiles can be used).<P>
	160
	161	You can't beat Cygwin's price (free), and you can debug adequately using gdb. However, it's
	162	quite slow to compile since it does not use precompiled headers.<P>
	163
	164	CodeWarrior is cross-platform - you can debug and generate Windows executables from a Mac, but not
	165	the other way around I think - but the IDE is, to my mind, a bit primitive.<P>
	166
	167	Watcom C++ is a little slow and the debugger is not really up to today's standards.<P>
	168
	169	Among the free compilers the best choice seem to be Borland C++ command line
	170	tools and mingw32 (port of gcc to Win32). Both of them are supported by
	171	wxWidgets.
	172
	173	<h3><a name="unicode">Is Unicode supported?</a></h3>
	174
	175	Yes, Unicode is fully supported under Windows NT/2000 and there is limited
	176	support for it under Windows 9x using <a
	177	href="http://www.microsoft.com/globaldev/handson/dev/mslu_announce.mspx">MSLU</a>.
	178	<p>
	179
	180	<h3><a name="doublebyte">Does wxWidgets support double byte fonts (Chinese/Japanese/Korean etc.)?</a></h3>
	181
	182	For Japanese under Win2000, it seems that wxWidgets has no problems to work
	183	with double byte char sets (meaning DBCS, not Unicode). First you have to
	184	install Japanese support on your Win2K system and choose for ANSI translation
	185	<tt>HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\CodePage=932</tt>
	186	(default is 1252 for Western). Then you can see all the Japanese letters in
	187	wxWidgets applications.
	188	<p>
	189
	190	<h3><a name="dll">Can you compile wxWidgets 2 as a DLL?</a></h3>
	191
	192	Yes (using the Visual C++ or Borland C++ makefile), but be aware that distributing DLLs is a thorny issue
	193	and you may be better off compiling statically-linked applications, unless you're
	194	delivering a suite of separate programs, or you're compiling a lot of wxWidgets applications
	195	and have limited hard disk space.<P>
	196
	197	With a DLL approach, and with different versions and configurations of wxWidgets
	198	needing to be catered for, the end user may end up with a host of large DLLs in his or her Windows system directory,
	199	negating the point of using DLLs. Of course, this is not a problem just associated with
	200	wxWidgets!
	201	<P>
	202
	203	<h3><a name="exesize">How can I reduce executable size?</a></h3>
	204
	205	You can compile wxWidgets as a DLL (see above, VC++/BC++ only at present). You should also
	206	compile your programs for release using non-debugging and space-optimisation options, but
	207	take with VC++ 5/6 space optimisation: it can sometimes cause problems.<P>
	208
	209	If you want to distribute really small executables, you can
	210	use <a href="http://www.un4seen.com/petite/" target=_top>Petite</a>
	211	by Ian Luck. This nifty utility compresses Windows executables by around 50%, so your 500KB executable
	212	will shrink to a mere 250KB. With this sort of size, there is reduced incentive to
	213	use DLLs. Another good compression tool (probably better than Petite) is <a href="http://upx.sourceforge.net/" target=_top>UPX</a>.
	214	<P>
	215
	216	Please do not be surprised if MinGW produces a statically-linked minimal executable of 1 MB. Firstly, gcc
	217	produces larger executables than some compilers. Secondly, this figure will
	218	include most of the overhead of wxWidgets, so as your application becomes more
	219	complex, the overhead becomes proportionally less significant. And thirdly, trading executable compactness
	220	for the enormous increase in productivity you get with wxWidgets is almost always well worth it.<P>
	221
	222	If you have a really large executable compiled with MinGW (for example 20MB) then
	223	you need to configure wxWidgets to compile without debugging information: see
	224	docs/msw/install.txt for details. You may find that using configure instead
	225	of makefile.g95 is easier, particularly since you can maintain debug and
	226	release versions of the library simultaneously, in different directories.
	227	Also, run 'strip' after linking to remove all traces of debug info.
	228	<P>
	229
	230	<H3><a name="mfc">Is wxWidgets compatible with MFC?</a></H3>
	231
	232	There is a sample which demonstrates MFC and wxWidgets code co-existing in the same
	233	application. However, don't expect to be able to enable wxWidgets windows with OLE-2
	234	functionality using MFC.<P>
	235
	236	<H3><a name="setuph">Why do I get errors about setup.h not being found?</a></H3>
	237
	238	When you build the wxWidgets library, setup.h is copied
	239	from include/wx/msw/setup.h to e.g. lib/mswd/wx/setup.h (the path
	240	depends on the configuration you're building). So you need to add
	241	this include path if building using the static Debug library:<P>
	242
	243	lib/mswd<P>
	244
	245	or if building the static Release library, lib/msw.<P>
	246
	247	See also the <a href="http://wiki.wxwidgets.org/wiki.pl?Table_Of_Contents">wxWiki Contents</a>
	248	for more information.<P>
	249
	250
	251	<H3><a name="asuffix">Why do I get errors about FooBarA when I only use FooBar in my program?</H3>
	252
	253	If you get errors like
	254	<p>
	255	<center>
	256	<tt>no matching function for call to 'wxDC::DrawTextA(const char[5], int,
	257	int)'</tt>
	258	</center>
	259	<p>
	260	or similar ones for the other functions, i.e. the compiler error messages
	261	mention the function with the <tt>'A'</tt> suffix while you didn't
	262	use it in your code, the explanation is that you had included
	263	<tt><windows.h></tt> header which redefines many symbols to have such
	264	suffix (or <tt>'W'</tt> in the Unicode builds).
	265
	266	<p>
	267	The fix is to either not include <tt><windows.h></tt> at all or include
	268	<tt>"wx/msw/winundef.h"</tt> immediately after it.
	269
	270	<H3><a name="newerrors">Why my code fails to compile with strange errors about new operator?</a></H3>
	271
	272	The most common cause of this problem is the memory debugging settings in
	273	<tt>wx/msw/setup.h</tt>. You have several choices:
	274
	275	<ul>
	276	<li> Either disable overloading the global operator new completely by
	277	setting <tt>wxUSE_GLOBAL_MEMORY_OPERATORS</tt> and
	278	<tt>wxUSE_DEBUG_NEW_ALWAYS</tt> to 0 in this file
	279	<li> Or leave them on but do <tt>#undef new</tt> after including any
	280	wxWidgets headers, like this the memory debugging will be still on
	281	for wxWidgets sources but off for your own code
	282	</ul>
	283
	284	Notice that IMHO the first solution is preferable for VC++ users who can use
	285	the <a href="#vcdebug">VC++ CRT memory debugging features</a> instead.
	286
	287	<H3><a name="mfcport">How do I port MFC applications to wxWidgets?</a></H3>
	288
	289	Set up your interface from scratch using wxWidgets (especially <a href="http://www.robeling.de" target=_top>wxDesigner</a>
	290	or <a href="http://www.anthemion.co.uk/dialogblocks/" target=_new>DialogBlocks</a> --
	291	it'll save you a <i>lot</i> of time) and when you have a shell prepared, you can start
	292	'pouring in' code from the MFC app, with appropriate
	293	modifications. This is the approach I have used, and I found
	294	it very satisfactory. A two-step process then - reproduce the bare
	295	interface first, then wire it up afterwards. That way you deal
	296	with each area of complexity separately. Don't try to think MFC
	297	and wxWidgets simultaneously from the beginning - it is easier to
	298	reproduce the initial UI by looking at the behaviour of the MFC
	299	app, not its code.
	300
	301	<H3><a name="crash">Why do I sometimes get bizarre crash problems using VC++ 5/6?</a></H3>
	302
	303	Some crash problems can be due to inconsistent compiler
	304	options (and of course this isn't limited to wxWidgets).
	305	If strange/weird/impossible things start to happen please
	306	check (dumping IDE project file as makefile and doing text comparison
	307	if necessary) that the project settings, especially the list of defined
	308	symbols, struct packing, etc. are exactly the same for all items in
	309	the project. After this, delete everything (including PCH) and recompile.<P>
	310
	311	VC++ 5's optimization code seems to be broken and can
	312	cause problems: this can be seen when deleting an object Dialog
	313	Editor, in Release mode with optimizations on. If in doubt,
	314	switch off optimisations, although this will result in much
	315	larger executables. It seems possible that the library can be created with
	316	strong optimization, so long as the application is not strongly
	317	optimized. For example, in wxWidgets project, set to 'Minimum
	318	Size'. In Dialog Editor project, set to 'Customize: Favor Small
	319	Code' (and no others). This will then work.<P>
	320
	321	<H3><a name="makefiles">How are the wxWidgets makefiles edited under Windows?</a></H3>
	322
	323	As of wxWidgets 2.1, there is a new system written by Vadim Zeitlin, that
	324	generates the makefiles from templates using tmake.<P>
	325
	326	Here are Vadim's notes:<P>
	327
	328	<blockquote>
	329	To use these new makefiles, you don't need anything (but see below).
	330	However, you should NOT modify them because these files will be
	331	rewritten when I regenerate them using tmake the next time. So, if
	332	you find a problem with any of these makefiles (say, makefile.b32)
	333	you'll need to modify the corresponding template (b32.t in this
	334	example) and regenerate the makefile using tmake.<P>
	335
	336	tmake can be found at
	337	<a href="http://www.troll.no/freebies/tmake.html" target=_new>www.troll.no/freebies/tmake.html</a>.
	338	It's a Perl5 program and so it needs Perl (doh). There is a binary for
	339	Windows (available from the same page), but I haven't used it, so
	340	I don't know if it works as flawlessly as "perl tmake" does (note
	341	for people knowing Perl: don't try to run tmake with -w, it won't
	342	do you any good). Using it extremely simple: to regenerate makefile.b32
	343	just go to distrib/msw/tmake and type<P>
	344
	345	<pre>tmake -t b32 wxwin.pro -o ../../src/msw/makefile.b32</pre><P>
	346
	347	The makefiles are untested - I don't have any of Borland, Watcom or
	348	Symantec and I don't have enough diskspace to recompile even with
	349	VC6 using makefiles. The new makefiles are as close as possible to the
	350	old ones, but not closer: in fact, there has been many strange things
	351	(should I say bugs?) in some of makefiles, some files were not compiled
	352	without any reason etc. Please test them and notify me about any problems.
	353	Better yet, modify the template files to generate the correct makefiles
	354	and check them in.<P>
	355
	356	The templates are described in tmake ref manual (1-2 pages of text)
	357	and are quite simple. They do contain some Perl code, but my Perl is
	358	primitive (very C like) so it should be possible for anybody to make
	359	trivial modifications to it (I hope that only trivial modifications
	360	will be needed). I've tagged the ol makefiles as MAKEFILES_WITHOUT_TMAKE
	361	in the cvs, so you can always retrieve them and compare the new ones,
	362	this will make it easier to solve the problems you might have.<P>
	363
	364	Another important file is filelist.txt: it contains the list of all
	365	files to be compiled. Some of them are only compiled in 16/32 bit mode.
	366	Some other are only compiled with some compilers (others can't compile
	367	them) - all this info is contained in this file.<P>
	368
	369	So now adding a new file to wxWidgets is as easy as modifying filelist.txt
	370	(and Makefile.ams for Unix ports) and regenerating the makefiles - no
	371	need to modify all files manually any more.<P>
	372
	373	Finally, there is also a file vc6.t which I use myself: this one
	374	generates a project file for VC++ 6.0 (I didn't create vc5.t because
	375	I don't need it and can't test it, but it should be trivial to create
	376	one from vc6.t - probably the only things to change would be the
	377	version number in the very beginning and the /Z option - VC5 doesn't
	378	support edit-and=continue). This is not an officially supported way
	379	of building wxWidgets (that is, nobody guarantees that it will work),
	380	but it has been very useful to me and I hope it will be also for
	381	others. To generate wxWidgets.dsp run<P>
	382
	383	<pre>tmake -t vc6 wxwin.pro -o ../../wxWidgets.dsp</pre><P>
	384
	385	Then just include this project in any workspace or open it from VC IDE
	386	and it will create a new workspace for you.<P>
	387
	388	If all goes well, I'm planning to create a template file for Makefile.ams
	389	under src/gtk and src/motif and also replace all makefiles in the samples
	390	subdirectories with the project files from which all the others will be
	391	generated. At least it will divide the number of files in samples
	392	directory by 10 (and the number of files to be maintained too).
	393	</blockquote>
	394
	395	<P>
	396
	397	<H3><a name="vcdebug">How do you use VC++'s memory leak checking instead of that in wxWidgets?</a></H3>
	398
	399	Vadim Zeitlin:
	400
	401	<pre>
	402	On the VC++ level, it's just the matter of calling _CrtSetDbgFlag() in the very
	403	beginning of the program. In wxWidgets, this is done automatically when
	404	compiling with VC++ in debug mode unless wxUSE_GLOBAL_MEMORY_OPERATORS or
	405	__NO_VC_CRTDBG__ are defined - this check is done in wx/msw/msvcrt.h which
	406	is included from app.cpp which then calls wxCrtSetDbgFlag() without any
	407	ifdefs.
	408
	409	This works quite well: at the end of the program, all leaked blocks with their
	410	malloc count are shown. This number (malloc count) can be used to determine
	411	where exactly the object was allocated: for this it's enough to set the variable
	412	_crtBreakAlloc (look in VC98\crt\srs\dbgheap.c line 326) to this number and
	413	a breakpoint will be triggered when the block with this number is allocated.
	414
	415	For simple situations it works like a charm. For something more complicated
	416	like reading uninitialized memory a specialized tool is probably better...
	417
	418	Regards,
	419	VZ
	420	</pre>
	421
	422	<P>
	423
	424	<H3><a name="shortcutproblem">Why are menu hotkeys or shortcuts not working in my application?</a></H3>
	425
	426	This can happen if you have a child window intercepting EVT_CHAR events and swallowing
	427	all keyboard input. You should ensure that event.Skip() is called for all input that
	428	isn'used by the event handler.<P>
	429
	430	It can also happen if you append the submenu to the parent
	431	menu {\it before} you have added your menu items. Do the append {\it after} adding
	432	your items, or accelerators may not be registered properly.<P>
	433
	434	<H3><a name="#regconfig">Why can I not write to the HKLM part of the registry with wxRegConfig?</a></H3>
	435
	436	Currently this is not possible because the wxConfig family of classes is
	437	supposed to deal with per-user application configuration data, and HKLM is
	438	only supposed to be writeable by a user with Administrator privileges. In theory,
	439	only installers should write to HKLM. This is still a point debated by the
	440	wxWidgets developers. There are at least two ways to work around it if you really
	441	need to write to HKLM.<P>
	442
	443	First, you can use wxRegKey directly, for example:
	444
	445	<pre>
	446	wxRegKey regKey;
	447
	448	wxString idName(wxT("HKEY_LOCAL_MACHINE\\SOFTWARE\\My Company\\My Product\\Stuff\\"));
	449	idName += packid;
	450
	451	regKey.SetName(idName);
	452
	453	{
	454	wxLogNull dummy;
	455	if (!regKey.Create())
	456	{
	457	idName = wxT("HKEY_CURRENT_USER\\SOFTWARE\\My Company\\My Product\\Stuff\\");
	458	idName += packid;
	459	regKey.SetName(idName);
	460	if (!regKey.Create())
	461	return FALSE;
	462	}
	463	}
	464
	465	if (!regKey.SetValue(wxT("THING"), (long) thing)) err += 1;
	466
	467	regKey.Close();
	468
	469	</pre>
	470
	471	Or, you can employ this trick suggested by Istvan Kovacs:
	472
	473	<pre>
	474	class myGlobalConfig : public wxConfig
	475	{
	476	myGlobalConfig() :
	477	wxConfig ("myApp", "myCompany", "", "", wxCONFIG_USE_GLOBAL_FILE)
	478	{};
	479	bool Write(const wxString& key, const wxString& value);
	480	}
	481
	482	bool myGlobalConfig::Write (const wxString& key, const wxString& value)
	483	{
	484	wxString path = wxString ("SOFTWARE\\myCompany\\myApp\\") + wxPathOnly(key);
	485	wxString new_path = path.Replace ("/", "\\", true);
	486	wxString new_key = wxFileNameFromPath (key);
	487	LocalKey().SetName (wxRegKey::HKLM, path);
	488	return wxConfig::Write (new_key, value);
	489	}
	490	</pre>
	491
	492	<H3><a name="#access">Is MS Active Accessibility supported?</a></H3>
	493
	494	This is being worked on. Please see <a href="http://www.wxwidgets.org/access.htm">this page</a>
	495	for the current status.
	496
	497	<P>
	498
	499
	500	<h3><a name="#dspfmt">Why does Visual C++ complain about corrupted project files??</a></h3>
	501
	502	If you have downloaded the wxWidgets sources from the cvs using a Unix cvs
	503	client or downloaded a daily snapshot in <tt>.tar.gz</tt> format, it is likely
	504	that the project files have Unix line endings (LF) instead of the DOS ones (CR
	505	LF). However all versions of Visual C++ up to and including 7.1 can only open
	506	the files with the DOS line endings, so you must transform the files to this
	507	format using any of the thousands ways to do it.
	508	<p>
	509	Of course, another possibility is to always use only the Windows cvs client
	510	and to avoid this problem completely.
	511	<p>
	512
	513	<h3><a name="#crtmismatch">Visual C++ gives errors about multiply defined symbols, what can I do?</a></h3>
	514
	515	If you get errors like this
	516
	517	<pre>
	518	MSVCRTD.lib(MSVCRTD.dll) : error LNK2005: _xxxxxx already defined in LIBCD.lib(yyyyy.obj)
	519	</pre>
	520
	521	when linking your project, this means that you used different versions of CRT
	522	(C Run-Time) library for wxWindows (or possibly another library) and the main
	523	project. Visual C++ provides static or dynamic and multithread safe or not
	524	versions of CRT for each of debug and release builds, for a total of 8
	525	libraries. You can choose among them by going to the "Code generation"
	526	page/subitem of the "C++" tab/item in the project proprieties dialog in VC6/7.
	527	<p>
	528	To avoid problems, you <strong>must</strong> use the same one for all
	529	components of your project. wxWindows uses multithread safe DLL version of the
	530	CRT which is a good choice but may be problematic when distributing your
	531	applications if you don't include the CRT DLL in your installation -- in this
	532	case you may decide to switch to using a static CRT version. If you build with
	533	<tt>wxUSE_THREADS == 0</tt> you may also use the non MT-safe version as it is
	534	slightly smaller and faster.
	535	<p>
	536	But the most important thing is to use the <strong>same</strong> CRT setting for
	537	all components of your project.
	538
	539	</font>
	540
	541	</BODY>
	542
	543	</HTML>