Question

我的项目由几个子项目组成，其中一个子项目包括QGIS库。

.pro文件：

TEMPLATE = subdirs

CONFIG += ordered

SUBDIRS += \
    Utils \
    Maps \
    GoogleMapsInterface \   
    Positioning \
    NetworkObjects \
    DataBaseManager \
    SensorNetworkUI \

这是Maps的.pro文件，其中包含QGIS库：

CONFIG += c++11
CONFIG += staticlib
TEMPLATE = lib
QT += core gui
QT += widgets
QT += xml

TARGET = maps

DEFINES += MAPS_INTERFACE

INCLUDEPATH += "C:/OSGeo4W/apps/qgis/include/"
INCLUDEPATH += "C:/OSGeo4W/include/"

win32:CONFIG(Release, Debug|Release) {
 LIBS += -LC:/OSGeo4W/lib/ -lQtCore4
 LIBS += -LC:/OSGeo4W/lib/ -lQtGui4
 LIBS += -LC:/OSGeo4W/lib/ -lQtXml4
}

else:win32:CONFIG(Debug, Debug|Release) {
 PRE_TARGETDEPS += C:/OSGeo4W/lib/QtCored4.lib
 PRE_TARGETDEPS += C:/OSGeo4W/lib/QtGuid4.lib
 PRE_TARGETDEPS += C:/OSGeo4W/lib/QtXmld4.lib
 LIBS += -LC:/OSGeo4W/lib/ -lQtCored4
 LIBS += -LC:/OSGeo4W/lib/ -lQtGuid4
 LIBS += -LC:/OSGeo4W/lib/ -lQtXmld4
}

LIBS += -LC:/OSGeo4W/lib -lgdal_i -lgeos_c
LIBS += -LC:/OSGeo4W/apps/qgis-dev/lib -lqgis_core -lqgis_gui

DEFINES += CORE_EXPORT=__declspec(dllexport)
DEFINES += GUI_EXPORT=__declspec(dllexport)

这是SensorNetworkUI的.pro文件：

CONFIG += console
TARGET = SensorNetwork
TEMPLATE = app

greaterThan(QT_MAJOR_VERSION, 4):
QT += widgets
QT += core gui
QT += opengl
QT += sql
QT += xml
QT += multimedia

INCLUDEPATH += ../
INCLUDEPATH += "C:/OSGeo4W/apps/qgis/include/"
INCLUDEPATH += "C:/OSGeo4W/include/"

win32:CONFIG(Release, Debug|Release) {
 LIBS += -LC:/OSGeo4W/lib/ -lQtCore4
 LIBS += -LC:/OSGeo4W/lib/ -lQtGui4
 LIBS += -LC:/OSGeo4W/lib/ -lQtXml4
}

else:win32:CONFIG(Debug, Debug|Release) {
 PRE_TARGETDEPS += C:/OSGeo4W/lib/QtCored4.lib
 PRE_TARGETDEPS += C:/OSGeo4W/lib/QtGuid4.lib
 PRE_TARGETDEPS += C:/OSGeo4W/lib/QtXmld4.lib
 LIBS += -LC:/OSGeo4W/lib/ -lQtCored4
 LIBS += -LC:/OSGeo4W/lib/ -lQtGuid4
 LIBS += -LC:/OSGeo4W/lib/ -lQtXmld4
}

DEFINES += CORE_EXPORT=__declspec(dllexport)
DEFINES += GUI_EXPORT=__declspec(dllexport)

LIBS += -LC:/OSGeo4W/lib -lgdal_i -lgeos_c
LIBS += -LC:/OSGeo4W/apps/qgis-dev/lib -lqgis_core -lqgis_gui
LIBS += -L../ -ldbmanager -lsnobjects -lpositioning -lsnutils -lmaps

但是，我收到的错误是这样的：

maps.lib(moc_ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)
MainWindow.obj : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)

我还注意到Qt Creator提供的自动完成建议不包含QGIS头文件。这是否意味着Qt Creator无法找到它们？一旦输出整个名称，它不会抛出错误。我甚至可以在Qt Creator中打开头文件。

有人可以告诉我哪里出错了吗？

编辑：这是错误开始的地方：

Creating library ..\SensorNetwork.lib and object ..\SensorNetwork.exp
maps.lib(moc_ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)
MainWindow.obj : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)
maps.lib(MapCanvas.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)
maps.lib(ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)
maps.lib(moc_MapCanvas.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsFeature const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsFeature@@PAV2@@Z)
maps.lib(moc_ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsExpressionContext const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsExpressionContext@@PAV2@@Z)
MainWindow.obj : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsExpressionContext const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsExpressionContext@@PAV2@@Z)
maps.lib(MapCanvas.obj) : error LNK2001: unresolved external symbol "public: virtual class QVariant __thiscall QgsExpression::Function::func(class QList<class QVariant> const &,class QgsExpressionContext const *,class QgsExpression *)" (?func@Function@QgsExpression@@UAE?AVQVariant@@ABV?$QList@VQVariant@@@@PBVQgsExpressionContext@@PAV2@@Z)
...
...
maps.lib(MapCanvas.obj) : error LNK2001: unresolved external symbol "public: static struct QMetaObject const QgsRasterDataProvider::staticMetaObject" (?staticMetaObject@QgsRasterDataProvider@@2UQMetaObject@@B)
maps.lib(MapCanvas.obj) : error LNK2001: unresolved external symbol "public: static struct QMetaObject const QgsRasterLayer::staticMetaObject" (?staticMetaObject@QgsRasterLayer@@2UQMetaObject@@B)
maps.lib(ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual void __thiscall QgsMapTool::renderComplete(void)" (?renderComplete@QgsMapTool@@UAEXXZ)
maps.lib(ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual bool __thiscall QgsMapTool::isTransient(void)const " (?isTransient@QgsMapTool@@UBE_NXZ)
maps.lib(ClickTool.obj) : error LNK2001: unresolved external symbol "public: virtual bool __thiscall QgsMapTool::isEditTool(void)const " (?isEditTool@QgsMapTool@@UBE_NXZ)
..\SensorNetwork.exe : fatal error LNK1120: 93 unresolved externals
jom: D:\Atmika\Sensor_Network\build\win32\Debug\SensorNetworkUI\Makefile.Debug [..\SensorNetwork.exe] Error 1120
jom: D:\Atmika\Sensor_Network\build\win32\Debug\SensorNetworkUI\Makefile [debug] Error 2
14:21:50: The process "D:\Qt\Qt5.7.1\Tools\QtCreator\bin\jom.exe" exited with code 2.
Error while building/deploying project Sensor_Network (kit: Desktop Qt 5.7.1 MSVC2015 32bit)
When executing step "Make"

Answer 1

您的错误肯定指向链接器未在库中找到正确的符号，如“错误LNK”所示，因此先前已正确找到标头。

找不到QGIS的核心库
由于您的某个项目中缺少相关性LIBS += ...，核心库未链接
使用与您不同的编译器编译库，产生编译器无法理解的ABI
您的标题和实际的图书馆不同（例如，如果他们指向不同版本的QGIS）。

您应该检查您指向的库文件是否存在并且对应于正确版本的QGIS。如果动态链接，还要确保所有项目取决于它实际上包含链接器指令LIBS += ...。

编辑：OP发现问题只是dllexport，应该是 dllimport 而不是QGIS CORE_EXPORT和GUI_EXPORT变量：

DEFINES += CORE_EXPORT=__declspec(dllimport)
DEFINES += GUI_EXPORT=__declspec(dllimport)

作为QGIS参考的详细记录的网站： https://3nids.wordpress.com/

QGIS在Qt Creator中使用独立的C ++应用程序

1 个答案: