曾经在两年前搞过一段时间的opencv，很多东西都忘记了，最近想重新捡起来玩一下。
背景是这样的：两年前是在Windows下，cmake+VS+Qt(4.7)
这次是Linux下 cmake + gcc+Qt(5.8)
对于Qt我是老手啦，两年前就开始摸了，然而这次却遇到了很奇怪的问题。
首先一步步地完成了opencv的编译和安装，却倒在了测试这一步：总是提示cv::xxx函数找不到，纠结了很久，今日终于解决。
根据stackoverflow上说的
https://stackoverflow.com/questions/37671406/compiling-programs-in-opencv：
首先起了一个shell，输入如下命令：pkg-config --libs opencv然后就会出来这些：（如果不清楚pkg-config请自行百度）
-L/usr/local/lib -lopencv_shape -lopencv_stitching -lopencv_objdetect -lopencv_superres -lopencv_videostab -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_photo -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_core
是的，你没看错，把这个加到你的工程里就好了！
我的.pro文件：
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TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle
CONFIG -= qt
INCLUDEPATH += /usr/local/include/opencv2 \
/usr/local/include/opencv
LIBS += -L/usr/local/lib -lopencv_shape -lopencv_stitching -lopencv_objdetect -lopencv_superres -lopencv_videostab -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_photo -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_core
SOURCES += main.cpp
——————————————————————————————————————————————————————————————————————————————
然后就能赤裸裸滴运行了！
不加这个路径不行，暂时还不清楚为何，毕竟我特么ldconfig过
-L/usr/local/lib