CMakeLists.txt加载第三方库

TgMath.h

#ifndef TGMATH_H
#define TGMATH_H

#include "tgmath_global.h"
class TGMATHSHARED_EXPORT TgMath
{
public:
    TgMath();

    static int add(const int a, const int b);
};

#endif // TGMATH_H

TgMath.cpp

#include "TgMath.h"

TgMath::TgMath()
{

}

int TgMath::add(const int a, const int b)
{
    return a + b;
}

CMakeLists.txt

project(lesson001)

# 使用Qt的模块
set(QT Core Widgets)
find_package(Qt5 COMPONENTS REQUIRED ${QT})

include_directories( /opt/TgMath/include )

link_directories( /opt/TgMath/lib )

add_executable(lesson001 lesson001.cpp)

target_link_libraries(lesson001 TgMath ${OpenCV_LIBS})

qt5_use_modules(lesson001 ${QT})

关键三行
include_directories： 指定库的头文件所在目录
link_directories： 指定库文件所在目录
target_link_libraries： 链接库文件

lesson001.cpp

#include 
#include 
#include "TgMath.h"

int main(int argc, char *argv[])
{
    qDebug() << "application start";

    qDebug() << "TgMath::add(5, 8) " << TgMath::add(5, 8);

	return 0;
}