How to copy Qt runtime DLLs to project output

Question

I have a simple project created in Qt Creator (installed using Qt SDK 1.1.4). It runs just fine from within Qt Creator, but if I then browse to the output directory in Windows

Answer 1

OK, here's an ugly hack:

# Copy required DLLs to output directory
CONFIG(debug, debug|release) {
    QtCored4.commands = copy /Y %QTDIR%\\bin\\QtCored4.dll debug
    QtCored4.target = debug/QtCored4.dll
    QtGuid4.commands = copy /Y %QTDIR%\\bin\\QtGuid4.dll debug
    QtGuid4.target = debug/QtGuid4.dll

    QMAKE_EXTRA_TARGETS += QtCored4 QtGuid4
    PRE_TARGETDEPS += debug/QtCored4.dll debug/QtGuid4.dll
} else:CONFIG(release, debug|release) {
    QtCore4.commands = copy /Y %QTDIR%\\bin\\QtCore4.dll release
    QtCore4.target = release/QtCore4.dll
    QtGui4.commands = copy /Y %QTDIR%\\bin\\QtGui4.dll release
    QtGui4.target = release/QtGui4.dll

    QMAKE_EXTRA_TARGETS += QtCore4 QtGui4
    PRE_TARGETDEPS += release/QtCore4.dll release/QtGui4.dll
} else {
    error(Unknown set of dependencies.)
}

Here's some of what I don't like about it:

• Uses %QTDIR% environment variable; this variable isn't evaluated until the copy command is actually run. Seems like something along the lines of QMAKE_LIBS_QT_DLL would be more appropriate, but I couldn't get that working for some reason.
• Hard-coded "debug" and "release" names; seems like there ought to be some kind of variable to use for that.
• Calling out to the environment by using the "copy" command.

I'll accept another answer if somebody can clean this up a good bit, for example by shortening it and/or addressing some of my concerns, or just finding a better way in general.