qt - 使用 QT 支持构建 OpenCV 时未解析的符号 QMetaObject

Question

我在构建支持 QT 的 OpenCV_HighGui220d.lib 时遇到问题。问题是关于QMetaObject的未解析符号，例如:

    public: virtual struct QMetaObject const * __thiscall GuiReceiver::metaObject(void)const (?metaObject@GuiReceiver@@UBEPBUQMetaObject@@XZ)

我的环境:
- Visual Studio 2010
- OpenCV 2.2
- QT SDK 版本:4.7.3

以下是我的搭建步骤:
1. 使用CMake打开C:\OpenCV2.2，勾选WITH_QT和WITH_QT_OPENGL，生成vcxproj和sln文件。

2.在 cvconfig.h 中添加以下宏:

<code>#define HAVE_QT</code>
<code>#define HAVE_QT_OPENGL</code>

3.在VS2010的opencv_highgui.vcxproj文件中添加window_QT.cpp，并在window_QT.cpp中添加如下宏

<code>#define QT_LARGEFILE_SUPPORT</code>
<code>#define QT_DLL</code>
<code>#define QT_GUI_LIB</code>
<code>#define QT_CORE_LIB</code>
<code>#define QT_HAVE_MMX</code>
<code>#define QT_HAVE_3DNOW</code>
<code>#define QT_HAVE_SSE</code>
<code>#define QT_HAVE_MMXEXT</code>
<code>#define QT_HAVE_SSE2</code>
<code>#define QT_THREAD_SUPPORT</code>

我也尝试过用 QT_NODLL替换 QT_DLL，但是没有成功。

4.添加目录 C:/QtSDK/Desktop/Qt/4.7.3/msvc2008/lib in Additional Library Directories in Linker Property pages.

5. 在Additional Dependencies中添加以下库:

qtmain.lib
qtmaind.lib
QtGui4.lib
QtGuid4.lib
QtCore4.lib
QtCored4.lib
QtOpenGL4.lib
QtOpenGLd4.lib
Qt3Support4.lib
Qt3Supportd4.lib
QtHelp4.lib
QtHelpd4.lib
QtDesigner4.lib
QtDesignerd4.lib
QAxContainer.lib
QAxContainerd.lib
phonon4.lib
phonond4.lib
QAxServer.lib
QAxServerd.lib
QtDeclarative4.lib
QtDeclaratived4.lib
QtDesignerComponents4.lib
QtDesignerComponentsd4.lib
QtMultimedia4.lib
QtMultimediad4.lib
QtNetwork4.lib
QtNetworkd4.lib
QtScript4.lib
QtScriptd4.lib
QtScriptTools4.lib
QtScriptToolsd4.lib
QtSql4.lib
QtSqld4.lib
QtSvg4.lib
QtSvgd4.lib
QtTest4.lib
QtTestd4.lib
QtUiTools.lib
QtUiToolsd.lib
QtWebKit4.lib
QtWebKitd4.lib
QtXml4.lib
QtXmld4.lib
QtXmlPatterns4.lib
QtXmlPatternsd4.lib

6.最后链接器报错:

------ Build started: Project: ZERO_CHECK, Configuration: Debug Win32 ------
------ Build started: Project: opencv_highgui, Configuration: Debug Win32 ------
     Creating library C:/OpenCV2.2/Build_QT/lib/Debug/opencv_highgui220d.lib and object C:/OpenCV2.2/Build_QT/lib/Debug/opencv_highgui220d.exp
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall GuiReceiver::metaObject(void)const " (?metaObject@GuiReceiver@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall GuiReceiver::qt_metacast(char const *)" (?qt_metacast@GuiReceiver@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall GuiReceiver::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@GuiReceiver@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvTrackbar::metaObject(void)const " (?metaObject@CvTrackbar@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvTrackbar::qt_metacast(char const *)" (?qt_metacast@CvTrackbar@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvTrackbar::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvTrackbar@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: static struct QMetaObject const CvTrackbar::staticMetaObject" (?staticMetaObject@CvTrackbar@@2UQMetaObject@@B)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvButtonbar::metaObject(void)const " (?metaObject@CvButtonbar@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvButtonbar::qt_metacast(char const *)" (?qt_metacast@CvButtonbar@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvButtonbar::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvButtonbar@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: static struct QMetaObject const CvButtonbar::staticMetaObject" (?staticMetaObject@CvButtonbar@@2UQMetaObject@@B)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvPushButton::metaObject(void)const " (?metaObject@CvPushButton@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvPushButton::qt_metacast(char const *)" (?qt_metacast@CvPushButton@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvPushButton::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvPushButton@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvCheckBox::metaObject(void)const " (?metaObject@CvCheckBox@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvCheckBox::qt_metacast(char const *)" (?qt_metacast@CvCheckBox@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvCheckBox::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvCheckBox@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvRadioButton::metaObject(void)const " (?metaObject@CvRadioButton@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvRadioButton::qt_metacast(char const *)" (?qt_metacast@CvRadioButton@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvRadioButton::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvRadioButton@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvWinProperties::metaObject(void)const " (?metaObject@CvWinProperties@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvWinProperties::qt_metacast(char const *)" (?qt_metacast@CvWinProperties@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvWinProperties::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvWinProperties@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall CvWindow::metaObject(void)const " (?metaObject@CvWindow@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall CvWindow::qt_metacast(char const *)" (?qt_metacast@CvWindow@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall CvWindow::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CvWindow@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: static struct QMetaObject const CvWindow::staticMetaObject" (?staticMetaObject@CvWindow@@2UQMetaObject@@B)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall ViewPort::metaObject(void)const " (?metaObject@ViewPort@@UBEPBUQMetaObject@@XZ)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall ViewPort::qt_metacast(char const *)" (?qt_metacast@ViewPort@@UAEPAXPBD@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: virtual int __thiscall ViewPort::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@ViewPort@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
window_QT.obj : error LNK2001: unresolved external symbol "public: static struct QMetaObject const ViewPort::staticMetaObject" (?staticMetaObject@ViewPort@@2UQMetaObject@@B)
C:\OpenCV2.2\Build_QT\bin\Debug\opencv_highgui220d.dll : fatal error LNK1120: 31 unresolved externals
========== Build: 1 succeeded, 1 failed, 8 up-to-date, 0 skipped ==========

Answer 1

Qt MOC(元对象编译器)未在您的 Qt 类文件上运行。

由于您是从 OpenCV 版本构建的，我假设 UI 类在类声明中已经有一个 Q_OBJECT 行。

要生成具有运行 MOC 所需构建指令的 .vcproj 文件，请运行以下命令:

qmake -tp vc -r <yourProFile.pro>

如果这不起作用，请右键单击其中一个包含 Qt 类的 .h 文件。在 Properties->Custom Build Step->General 下，您应该看到如下内容:

Command Line "$(QTDIR)\bin\moc.exe" -I".\GeneratedFiles\." -I"$(QTDIR)\include\." -I".\GeneratedFiles\$(ConfigurationName)\." -I"$(QTDIR)\include\QtCore\." -I"$(QTDIR)\include\QtGui\." .\GeneratedFiles\$(ConfigurationName)\moc_$(InputName).cpp" "-fstdafx.h" "-f[YourQtFile.h]"
Description Moc'ing $(InputFileName)...
Outputs ".\GeneratedFiles\$(ConfigurationName)\moc_$(InputName).cpp"
Additional Dependencies "$(QTDIR)\bin\moc.exe";$(InputPath)

希望这对您有所帮助。