
wxWidgets for Windows FAQ
See also top-level FAQ page.
List of questions in this category
wxWidgets can be used to develop and deliver applications on Windows 95, Windows 98, Windows NT,
Windows 2000, Windows XP, and Windows Vista. A Windows CE
port is also available (see below).
16-bit compilation is only supported for wxWidgets 2.4 and previous versions,
using Visual C++ 1.5 and Borland BC++ 4 to 5.
wxWidgets for Windows will also compile on Unix with gcc using Wine from WineHQ.
The resulting executables are Unix binaries that work with the Wine Windows API emulator.
You can also compile wxWidgets for Windows on Unix with Cygwin or Mingw32, resulting
in executables that will run on Windows. So in theory you could write your applications
using wxGTK or wxMotif, then check/debug your wxWidgets for Windows
programs with Wine, and finally produce an ix86 Windows executable using Cygwin/Mingw32,
without ever needing a copy of Microsoft Windows. See the Technical Note on the Web site detailing cross-compilation.
This port supports Pocket PC 2002/2003 and MS Smartphone 2002/2003, using
Embedded Visual C++ 3 or 4. For further information, see the wxMSW section in
the wxWidgets Reference Manual, and also the wxEmbedded page.
From wxWidgets 2.5, the XP manifest is included in wx/msw/wx.rc and
so your application will be themed automatically so long as you include wx.rc
in your own .rc file.
For versions of wxWidgets below 2.5, you need to provide the manifest
explicitly, as follows.
In the same directory as you have your executable (e.g. foo.exe) you
put a file called foo.exe.manifest in which you have something like
the following:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly
xmlns="urn:schemas-microsoft-com:asm.v1"
manifestVersion="1.0">
<assemblyIdentity
processorArchitecture="x86"
version="5.1.0.0"
type="win32"
name="foo.exe"/>
<description>Foo program</description>
<dependency>
<dependentAssembly>
<assemblyIdentity
type="win32"
name="Microsoft.Windows.Common-Controls"
version="6.0.0.0"
publicKeyToken="6595b64144ccf1df"
language="*"
processorArchitecture="x86"/>
</dependentAssembly>
</dependency>
</assembly>
If you want to add it to your application permanently,
you can also include it in your .rc file using this
line:
1 24 "winxp.manifest"
For an explanation of this syntax, please see
this
article.
Please see the wxWidgets for Windows install.txt file for up-to-date information, but
currently the following are known to work:
- Visual C++ 1.5, 4.0, 5.0, 6.0, 7.0, 7.1, 8.0
- Borland C++ 4.5, 5.0, 5.5
- Borland C++Builder 1.0, 3.0, X
- Watcom C++ 10.6 (Win32), OpenWatcom 1.0
- Cygwin (using configure)
- Mingw32
- MetroWerks CodeWarrior (many versions)
- Digital Mars 8.34+
It's partly a matter of taste, but some people prefer Visual C++ since the debugger is very
good, it's very stable, the documentation is extensive, and it generates small executables.
Since project files are plain text, it's easy for me to generate appropriate project files
for wxWidgets samples.
Borland C++ is fine - and very fast - but it's hard (impossible?) to use the debugger without using project files, and
the debugger is nowhere near up to VC++'s quality. The IDE isn't great.
C++Builder's power isn't really used with wxWidgets since it needs integration with its
own class library (VCL). For wxWidgets, I've only used it with makefiles, in which case
it's almost identical to BC++ 5.0 (the same makefiles can be used).
You can't beat Cygwin's price (free), and you can debug adequately using gdb. However, it's
quite slow to compile since it does not use precompiled headers.
CodeWarrior is cross-platform - you can debug and generate Windows executables from a Mac, but not
the other way around I think - but the IDE is, to my mind, a bit primitive.
Watcom C++ is a little slow and the debugger is not really up to today's standards.
Among the free compilers the best choice seem to be Borland C++ command line
tools and mingw32 (port of gcc to Win32). Both of them are supported by
wxWidgets. However BC++ has trouble compiling large executables statically,
so you need to dynamically link the wxWidgets libraries.
Yes, Unicode is fully supported under Windows NT/2000 and there is limited
support for it under Windows 9x using MSLU.
For Japanese under Win2000, it seems that wxWidgets has no problems working
with double byte char sets (meaning DBCS, not Unicode). First you have to
install Japanese support on your Win2K system and choose for ANSI translation
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\CodePage=932
(default is 1252 for Western). Then you can see all the Japanese letters in
wxWidgets applications.
Yes (using the Visual C++ or Borland C++ makefile), but be aware that distributing DLLs is a thorny issue
and you may be better off compiling statically-linked applications, unless you're
delivering a suite of separate programs, or you're compiling a lot of wxWidgets applications
and have limited hard disk space.
With a DLL approach, and with different versions and configurations of wxWidgets
needing to be catered for, the end user may end up with a host of large DLLs in his or her Windows system directory,
negating the point of using DLLs. Of course, this is not a problem just associated with
wxWidgets!
You can compile wxWidgets as a DLL (see above, VC++/BC++ only at present). You should also
compile your programs for release using non-debugging and space-optimisation options, but
take with VC++ 5/6 space optimisation: it can sometimes cause problems.
If you want to distribute really small executables, you can
use Petite
by Ian Luck. This nifty utility compresses Windows executables by around 50%, so your 500KB executable
will shrink to a mere 250KB. With this sort of size, there is reduced incentive to
use DLLs. Another good compression tool (probably better than Petite) is UPX.
Please do not be surprised if MinGW produces a statically-linked minimal executable of 1 MB. Firstly, gcc
produces larger executables than some compilers. Secondly, this figure will
include most of the overhead of wxWidgets, so as your application becomes more
complex, the overhead becomes proportionally less significant. And thirdly, trading executable compactness
for the enormous increase in productivity you get with wxWidgets is almost always well worth it.
If you have a really large executable compiled with MinGW (for example 20MB) then
you need to configure wxWidgets to compile without debugging information: see
docs/msw/install.txt for details. You may find that using configure instead
of makefile.g95 is easier, particularly since you can maintain debug and
release versions of the library simultaneously, in different directories.
Also, run 'strip' after linking to remove all traces of debug info.
There is a sample which demonstrates MFC and wxWidgets code co-existing in the same
application. However, don't expect to be able to enable wxWidgets windows with OLE-2
functionality using MFC.
When you build the wxWidgets library, setup.h is copied
from include/wx/msw/setup.h to e.g. lib/vc_msw/mswd/wx/setup.h (the path
depends on the configuration you're building). So you need to add
this include path if building using the static Debug library:
lib/vc_lib/mswd
or if building the static Release library, lib/vc_lib/msw.
See also the wxWiki Contents
for more information.
If you get errors like
no matching function for call to 'wxDC::DrawTextA(const char[5], int,
int)'
or similar ones for the other functions, i.e. the compiler error messages
mention the function with the 'A' suffix while you didn't
use it in your code, the explanation is that you had included
<windows.h> header which redefines many symbols to have such
suffix (or 'W' in the Unicode builds).
The fix is to either not include <windows.h> at all or include
"wx/msw/winundef.h" immediately after it.
The most common cause of this problem is the memory debugging settings in
wx/msw/setup.h. You have several choices:
- Either disable overloading the global operator new completely by
setting wxUSE_GLOBAL_MEMORY_OPERATORS and
wxUSE_DEBUG_NEW_ALWAYS to 0 in this file
- Or leave them on but do #undef new after including any
wxWidgets headers, like this the memory debugging will be still on
for wxWidgets sources but off for your own code
Notice that IMHO the first solution is preferable for VC++ users who can use
the
VC++ CRT memory debugging features instead.
Set up your interface from scratch using wxWidgets (especially
wxDesigner
or
DialogBlocks --
it'll save you a
lot of time) and when you have a shell prepared, you can start
'pouring in' code from the MFC app, with appropriate
modifications. This is the approach I have used, and I found
it very satisfactory. A two-step process then - reproduce the bare
interface first, then wire it up afterwards. That way you deal
with each area of complexity separately. Don't try to think MFC
and wxWidgets simultaneously from the beginning - it is easier to
reproduce the initial UI by looking at the behaviour of the MFC
app, not its code.
Some crash problems can be due to inconsistent compiler
options (and of course this isn't limited to wxWidgets).
If strange/weird/impossible things start to happen please
check (dumping IDE project file as makefile and doing text comparison
if necessary) that the project settings, especially the list of defined
symbols, struct packing, etc. are exactly the same for all items in
the project. After this, delete everything (including PCH) and recompile.
VC++ 5's optimization code seems to be broken and can
cause problems: this can be seen when deleting an object Dialog
Editor, in Release mode with optimizations on. If in doubt,
switch off optimisations, although this will result in much
larger executables. It seems possible that the library can be created with
strong optimization, so long as the application is not strongly
optimized. For example, in wxWidgets project, set to 'Minimum
Size'. In Dialog Editor project, set to 'Customize: Favor Small
Code' (and no others). This will then work.
This can happen if you have a child window intercepting EVT_CHAR events and swallowing
all keyboard input. You should ensure that event.Skip() is called for all input that
isn'used by the event handler.
It can also happen if you append the submenu to the parent menu before
you have added your menu items. Do the append after adding your items,
or accelerators may not be registered properly.
Currently this is not possible because the wxConfig family of classes is
supposed to deal with per-user application configuration data, and HKLM is
only supposed to be writeable by a user with Administrator privileges. In theory,
only installers should write to HKLM. This is still a point debated by the
wxWidgets developers. There are at least two ways to work around it if you really
need to write to HKLM.
First, you can use wxRegKey directly, for example:
wxRegKey regKey;
wxString idName(wxT("HKEY_LOCAL_MACHINE\\SOFTWARE\\My Company\\My Product\\Stuff\\"));
idName += packid;
regKey.SetName(idName);
{
wxLogNull dummy;
if (!regKey.Create())
{
idName = wxT("HKEY_CURRENT_USER\\SOFTWARE\\My Company\\My Product\\Stuff\\");
idName += packid;
regKey.SetName(idName);
if (!regKey.Create())
return FALSE;
}
}
if (!regKey.SetValue(wxT("THING"), (long) thing)) err += 1;
regKey.Close();
Or, you can employ this trick suggested by Istvan Kovacs:
class myGlobalConfig : public wxConfig
{
myGlobalConfig() :
wxConfig ("myApp", "myCompany", "", "", wxCONFIG_USE_GLOBAL_FILE)
{};
bool Write(const wxString& key, const wxString& value);
}
bool myGlobalConfig::Write (const wxString& key, const wxString& value)
{
wxString path = wxString ("SOFTWARE\\myCompany\\myApp\\") + wxPathOnly(key);
wxString new_path = path.Replace ("/", "\\", true);
wxString new_key = wxFileNameFromPath (key);
LocalKey().SetName (wxRegKey::HKLM, path);
return wxConfig::Write (new_key, value);
}
This is being worked on. Please see
this page
for the current status.
If you have downloaded the wxWidgets sources from the cvs using a Unix cvs
client or downloaded a daily snapshot in
.tar.gz format, it is likely
that the project files have Unix line endings (LF) instead of the DOS ones (CR
LF). However all versions of Visual C++ up to and including 7.1 can only open
the files with the DOS line endings, so you must transform the files to this
format using any of the thousands ways to do it.
Of course, another possibility is to always use only the Windows cvs client
and to avoid this problem completely.
If you get errors like this
MSVCRTD.lib(MSVCRTD.dll) : error LNK2005: _xxxxxx already defined in LIBCD.lib(yyyyy.obj)
when linking your project, this means that you used different versions of CRT
(C Run-Time) library for wxWindows (or possibly another library) and the main
project. Visual C++ provides static or dynamic and multithread safe or not
versions of CRT for each of debug and release builds, for a total of 8
libraries. You can choose among them by going to the "Code generation"
page/subitem of the "C++" tab/item in the project proprieties dialog in VC6/7.
To avoid problems, you must use the same one for all
components of your project. wxWindows uses multithread safe DLL version of the
CRT which is a good choice but may be problematic when distributing your
applications if you don't include the CRT DLL in your installation -- in this
case you may decide to switch to using a static CRT version. If you build with
wxUSE_THREADS == 0 you may also use the non MT-safe version as it is
slightly smaller and faster.
But the most important thing is to use the same CRT setting for
all components of your project.
If you get errors when including Microsoft DirectShow or DirectDraw headers,
the following message from Peter Whaite could help:
> This causes compilation errors within DirectShow:
>
> wxutil.h(125) : error C2065: 'EXECUTE_ASSERT' : undeclared identifier
> amfilter.h(1099) : error C2065: 'ASSERT' : undeclared identifier
The reason for this is that __WXDEBUG__ is also used by the DXSDK (9.0
in my case) to '#pragma once' the contents of
DXSDK/Samples/C++/DirectShow/BaseClasses/wxdebug.h. So if __WXDEBUG__
is defined, then wxdebug.h doesn't get included, and the assert macros
don't get defined. You have to #undef __WXDEBUG__ before including the
directshow baseclass's <streams.h>.
If you need to interface with native Windows code, you may use
wxWindow::GetHWND() method whose result can be cast to
HWND.
To handle a Windows message you need to override a virtual
MSWWindowProc() method in a wxWindow-derived class. You should then
test if
nMsg parameter is the message you need to process and perform
the necessary action if it is or call the base class method otherwise.