1.背景介紹

建議先查看之前的文章【CodeSys中調(diào)用C語言寫的動態(tài)庫】，了解如何創(chuàng)建一個能夠被codesys調(diào)用的動態(tài)庫。
假如想要在函數(shù)中使用Qt或者第三方庫（比如opencv等），可以在其自動生成的makefile文件中設置好相應的參數(shù)。

2.修改makefile

修改后的makefile：

##############################################################################
#	Copyright:		Copyright CODESYS Development GmbH
#	Program:		Extension API for the Linux SL products
###############################################################################
# with this makefile you can influence the build of your component 
#
#
# Hints:
#  - the name of the *Itf.m4 file in this folder will be used as name of the shared object (and component name)
#  - all C files in this folder will be compiled by default
# # set versions of your shared object
# must be single digit, decimal
MAJORVER=0
MINORVER=1# set a component version (must match your IEC library version)
# must be 4 bytes, hexadecimal
CMPVERSION=0x01000000# set a component ID 
# must be 2 bytes >= 0x2000 and hexadecimal and can be used to differentiate different components
CMPID=0x2000# set your tools
DOS2UNIX = dos2unix
M4 = m4# set a compiler
#CC = gcc
CC = g++#INCLUDEPATH += /usr/include/opencv4
#LIBS += /usr/lib/x86_64-linux-gnu/libopencv_*.so          #添加庫# add some compiler flags (with += )
#CFLAGS += -g# add some include paths (with +=)
#INCLUDES += -I.# add some linker flags (with += )
#LDFLAGS += # add some libraries that you might need (with += )
#LDLIBS += -lc# 為了能夠使用opencv而做的一些設置
INCLUDES += -I/usr/include/opencv4\-I/usr/include/opencv4/opencv2
LDLIBS += /usr/lib/x86_64-linux-gnu/libopencv_*.so# #為了能夠使用Qt而做的一些參數(shù)設置
INCLUDES += -I/opt/Qt/5.15.2/gcc_64/include\-I/opt/Qt/5.15.2/gcc_64/include/QtCore\-I/opt/Qt/5.15.2/gcc_64/mkspecs/linux-g++\-I/opt/Qt/5.15.2/gcc_64/include/QtRemoteObjects
LDLIBS += /opt/Qt/5.15.2/gcc_64/lib/*.so
LDFLAGS += -Wl,-rpath,/opt/Qt/5.15.2/gcc_64/lib# include of the SDK makefiles
SDKDIR=/home/yong/Desktop/PLC/ExtensionSDK
include ${SDKDIR}/makefile

主要是做了三個修改：

2.1.將編譯器由c改成c++

2.2.使能opencv庫

2.3.使能Qt庫

這里特別注意一下這個：-Wl,-rpath,/opt/Qt/5.15.2/gcc_64/lib，這條語句是指定了運行時搜索庫的路徑，沒有這句的話，雖然可以編譯通過，但是運行時codesys就直接報錯，無法下載了?？梢钥纯催@個資料的介紹【GCC/G++選項 -Wl,-rpath=】
我是如何知道需要寫這個的？我是從QtCreator的編譯輸出看到的：

3.在代碼中使用Qt庫函數(shù)

這樣操作之后，在include對應的頭文件后，就可以在函數(shù)中使用opencv、Qt了。