[SOLVED] How to use connect in a shared library?
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Hi
I've written an application, now I copied the functions in a shared library to make a dll.
Now I can see a weird error:#include "library1.h" Library1::Library1() { } void Library1::Inint_Lib() { if(Scan_Port()) { Serial=new QSerialPort; QObject::connect(Serial,SIGNAL(readyRead()),this,SLOT(Capture_Received_Data())); } }It's working in the application with GUI, but this error occurs in the shared library project:
Library1\library1.cpp:16: error: no matching function for call to 'QObject::connect(QSerialPort*&, const char*, Library1* const, const char*)' Library1\library1.cpp:16: candidates are: D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qiodevice.h:47: In file included from D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore/qiodevice.h:47:0, D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\QIODevice:1: from D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore/QIODevice:1, Library1\library1.h:7: from ..\Library1\library1.h:7, Library1\library1.cpp:1: from ..\Library1\library1.cpp:1: D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:198: static QMetaObject::Connection QObject::connect(const QObject*, const char*, const QObject*, const char*, Qt::ConnectionType) D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:201: static QMetaObject::Connection QObject::connect(const QObject*, const QMetaMethod&, const QObject*, const QMetaMethod&, Qt::ConnectionType) D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:201: note: no known conversion for argument 2 from 'const char*' to 'const QMetaMethod&' D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:440: QMetaObject::Connection QObject::connect(const QObject*, const char*, const char*, Qt::ConnectionType) const D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:440: note: no known conversion for argument 3 from 'Library1* const' to 'const char*' D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:214: template<class Func1, class Func2> static QMetaObject::Connection QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, const typename QtPrivate::FunctionPointer<Func2>::Object*, Func2, Qt::ConnectionType) D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:214: note: template argument deduction/substitution failed: D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:-1: In substitution of 'template<class Func1, class Func2> static QMetaObject::Connection QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, const typename QtPrivate::FunctionPointer<Func2>::Object*, Func2, Qt::ConnectionType) [with Func1 = const char*; Func2 = const char*]': \Library1\library1.cpp:16: required from here D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:214: error: no type named 'Object' in 'struct QtPrivate::FunctionPointer<const char*>' D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:244: template<class Func1, class Func2> static typename QtPrivate::QEnableIf<((int)(QtPrivate::FunctionPointer<Func2>::ArgumentCount) >= 0), QMetaObject::Connection>::Type QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, Func2) . . . D:\Qt-5.1.0\5.1.0\mingw48_32\include\QtCore\qobject.h:267: template<class Func1, class Func2> static typename QtPrivate::QEnableIf<(QtPrivate::FunctionPointer<Func2>::ArgumentCount == (-1)), QMetaObject::Connection>::Type QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, Func2) Library1\library1.cpp:16: note: candidate expects 3 arguments, 4 providedHow can I connect a signal to the library slot?
Thank you all -
Is the slot declared as a slot? Does live in a class that inherits from QObject, and is there Q_OBJECT macro there in the header?
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@Mohammadsm
I have added markdown tags for code sections of post.
Please checkout the "markdown tags" at the end of thread.@koahnig
I used code format but seems not working! -
@koahnig
I used code format but seems not working!@Mohammadsm
You need to use three of ` at start and end of your code block.Check the end of the whole thread here. There is a short explanation.
Some keyboards do not support ` as a key. In this case you can go to the end of the thread and copy the three characters required and paste them where needed.Vote the answer(s) that helped you to solve your issue(s)
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@Mohammadsm
You need to use three of ` at start and end of your code block.Check the end of the whole thread here. There is a short explanation.
Some keyboards do not support ` as a key. In this case you can go to the end of the thread and copy the three characters required and paste them where needed. -
@sierdzio
Yes :class LIBRARY1SHARED_EXPORT Library1 { Q_OBJECT public: Library1(); void Inint_Lib(); private slots: void Capture_Received_Data();[edit: koahnig, code markers]
Your class does not inherit from QObject. Try this:
class LIBRARY1SHARED_EXPORT Library1 : public QObjectThen remeber to rebuild and relink the library, and your project that uses it.
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Your class does not inherit from QObject. Try this:
class LIBRARY1SHARED_EXPORT Library1 : public QObjectThen remeber to rebuild and relink the library, and your project that uses it.
@sierdzio
It worked by adding ": public QObject"
Thank you, very much -
@sierdzio Indeed the back ticks are not mandatory, however it gives the forum engine a good hint of what is following
@SGaist said:
@sierdzio Indeed the back ticks are not mandatory, however it gives the forum engine a good hint of what is following
in the cheat sheet you can actually find:
Blocks of code are either fenced by lines with three back-ticks ```, or are indented with four spaces. I recommend only using the fenced code blocks -- they're easier and only they support syntax highlighting.The question is what is the syntax highlighting now?
