Preface

In the recently contacted projects, after the interface is divided, the dynamic library is used to deliver to colleagues for integration and call. Development environment Qt+VS, just getting started with VSa little cut to the heart, hereby record.

The creation of dynamic library in Qt

QtCreatorYou can create a dynamic library through the wizard, which is amazing.

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In the present example testdll, it is worth noting that:

pro

//...
TEMPLATE = lib
DEFINES += TESTDLL_LIBRARY

testdll_global.h

#ifndef TESTDLL_GLOBAL_H
#define TESTDLL_GLOBAL_H

#include <QtCore/qglobal.h>

#if defined(TESTDLL_LIBRARY)
#  define TESTDLLSHARED_EXPORT Q_DECL_EXPORT
#else
#  define TESTDLLSHARED_EXPORT Q_DECL_IMPORT
#endif

#endif // TESTDLL_GLOBAL_H

testdll.h

#ifndef TESTDLL_H
#define TESTDLL_H

#include "testdll_global.h"

class TESTDLLSHARED_EXPORT Testdll
{
    
    

public:
    Testdll();
};

#endif // TESTDLL_H

It can be found mainly through the macro definitions to control the header file classmodifier

Q_DECL_EXPORT
That __declspec(dllexport)indicates导出dll
Q_DECL_IMPORT
That __declspec(dllimport)indicates导入dll

Qt interface class

It is very easy to use the wizard.

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Create a new App; if you are writing an interface class, the general base class is selectedQWidget

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Dynamic library with interface

We only need to create the interface class and add the macro definition in the header file

#if defined(__DLL_LIBRARY)
#  define  xxx_EXPORT __declspec(dllexport)
#else
#  define xxx_EXPORT __declspec(dllimport)
#endif

And xxx_EXPORTmodifications toclass

It is noteworthy that __DLL_LIBRARYthe best in the project configuration is added in, avoid forget to change results in a compile error when packaging: Do not allow the definition of dllimport static data members.

In Qtthe middle can be pro文件added: