Qt5 - 鏈接pHash庫「未定義參考」

Question

我想添加一個名爲pHash的外部庫。我將此添加到.pro文件：

win32:CONFIG(release, debug|release): LIBS += -L$PWD/Libs/pHash-0.9.4/release -lpHash 
else:win32:CONFIG(debug, debug|release): LIBS += -L$PWD/Libs/pHash-0.9.4/debug -lpHash 

INCLUDEPATH += $PWD/Libs/pHash-0.9.4 
DEPENDPATH += $PWD/Libs/pHash-0.9.4 

win32:CONFIG(release, debug|release): PRE_TARGETDEPS += $PWD/Libs/pHash-0.9.4/release/pHash.lib 
else:win32:CONFIG(debug, debug|release): PRE_TARGETDEPS += $PWD/Libs/pHash-0.9.4/debug/pHash.lib 

但庫的沒有一個功能正在工作。當我嘗試使用一個，我有建立錯誤「未定義參考pHashFunction」。有使用的例子：

#include "myclass.h" 

#define HAVE_IMAGE_HASH 1 // config 
#include "pHash.h" 

void MyClass::perform() { 
    const char *msg = ph_about(); 
    qDebug() << msg; 
} 

再有就是生成日誌：

C:/Qt/Tools/mingw492_32/bin/mingw32-make -f Makefile.Debug clean 
mingw32-make[1]: Entering directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug' 
rm -f debug/qrc_qml.cpp 
rm -f debug/moc_myclass.cpp 
rm -f debug/main.o debug/myclass.o debug/qrc_qml.o debug/moc_myclass.o 
mingw32-make[1]: Leaving directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug' 
C:/Qt/Tools/mingw492_32/bin/mingw32-make -f Makefile.Release clean 
mingw32-make[1]: Entering directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug' 
rm -f release/qrc_qml.cpp 
rm -f release/moc_myclass.cpp 
rm -f release/main.o release/myclass.o release/qrc_qml.o release/moc_myclass.o 
mingw32-make[1]: Leaving directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug' 
01:31:34: Le processus "C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe" s'est terminé normalement. 
01:31:34: Configuration inchangée, étape qmake sautée. 
01:31:34: Débute : "C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe" 
C:/Qt/Tools/mingw492_32/bin/mingw32-make -f Makefile.Debug 
mingw32-make[1]: Entering directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug' 
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++ -o debug/main.o ../myProject/main.cpp 
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++ -o debug/myclass.o ../myProject/myclass.cpp 
In file included from ../myProject/myclass.cpp:3:0: 
../myProject/Libs/pHash-0.9.4/pHash.h:299:21: warning: 'cimg_library::CImg<float>* ph_dct_matrix(int)' declared 'static' but never defined [-Wunused-function] 
static CImg<float>* ph_dct_matrix(const int N); 
        ^
'C:\Qt\5.5\mingw492_32\bin\rcc.exe' -name qml ../myProject/qml.qrc -o debug/qrc_qml.cpp 
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++ -o debug/qrc_qml.o debug/qrc_qml.cpp 
'C:\Qt\5.5\mingw492_32\bin\moc.exe' -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -D__GNUC__ -DWIN32 -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++ -IC:/Users/vi/Documents/Programmation/QtWorkspace/myProject -IC:/Users/vi/Documents/Programmation/QtWorkspace/myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -I. ../myProject/myclass.h -o debug/moc_myclass.cpp 
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++ -o debug/moc_myclass.o debug/moc_myclass.cpp 
g++ -Wl,-subsystem,windows -mthreads -o debug/myProject.exe debug/main.o debug/myclass.o debug/qrc_qml.o debug/moc_myclass.o -lmingw32 -LC:/Qt/5.5/mingw492_32/lib -lqtmaind -lshell32 -LC:/Users/vi/Documents/Programmation/QtWorkspace/myProject/Libs/pHash-0.9.4/debug -lpHash -lQt5Quickd -lQt5Guid -lQt5Qmld -lQt5Networkd -lQt5Cored 
debug/myclass.o: In function `ZN6myclass7performEv': 
C:\Users\vi\Documents\Programmation\QtWorkspace\build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug/../myProject/myclass.cpp:11: undefined reference to `ph_about' 
collect2.exe: error: ld returned 1 exit status 
Makefile.Debug:83: recipe for target 'debug/myProject.exe' failed 
mingw32-make[1]: *** [debug/myProject.exe] Error 1 
mingw32-make[1]: Leaving directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug' 
makefile:34: recipe for target 'debug' failed 
mingw32-make: *** [debug] Error 2 

預先感謝您的幫助:)

Answer 1

嘗試添加的.c和.cpp到您的項目（dirent.c，ph_fft.c，pHash.cpp，phcomplex.c）它在我的電腦上工作，但我認爲問題是.dll和.lib與您的Qt版本不兼容，導致它被編譯與Visual Studio。

Answer 2

庫pHash不再被支持，並且存在許多問題。

1. 編譯器的MinGW 4.9.2使用Qt使用不帶內置MSVC .dll文件兼容。

2. 這是不夠用的伎倆"MSVC and MinGW DLLs"，因爲功能ph_about()不是從pHash.dll出口，例如Building the pHash library on Windows

3. 它可以整合所有pHash文件到Qt項目，所以該庫可與應用程序一起構建。由於圖書館項目是爲Visual Studio準備的，我會說Qt也應該基於VC。但是，圖書館的PHash很舊。它是爲Visual Studio 2008編寫的。現在，它在已棄用的Windows功能SHGetSpecialFolderPathA上出現錯誤。

4. 使用Qt MinGW 4.9.2編譯器編譯所有東西仍然很有用。在這種情況下，需要將DEFINES += HAVE_IMAGE_HASH=1添加到項目.pro文件中，以啓用該宏也用於編譯pHash。但是，要使用原生支持圖片庫libjpeg和libpng也應該用相同的編譯器編譯，例如Compiling libjpeg 如果不使用的圖像庫，Cimg嘗試運行一些外部可執行gm.exe（可能是從GraphicsMagick工具）。

如果需要一些快速的任務，可以考慮Linux虛擬磁帶庫，因爲在這裏可以開箱即用https://stackoverflow.com/a/33002746/4023446