CMake设置使用OpenCV的静态库

#cmake变量BUILD_SHARED_LIB 是一个全局变量
set(BUILD_SHARED_LIBS OFF)

#例如设置使用opencv的静态库
if(NOT DEFINED OpenCV_STATIC)
  # look for global setting
  if(NOT DEFINED BUILD_SHARED_LIBS OR BUILD_SHARED_LIBS)
    set(OpenCV_STATIC OFF)
  else()
    set(OpenCV_STATIC ON)
endif()