一  QT 上的 .pro 文件 将 linux，mac和windows上配置设置为可以共享

1. 先来看文件夹布局

2. 再来看 QT 中的 .pro文件

.pro 文件的写法

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    mainwindow.h

FORMS += \
    mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

# 添加windows的配置，这里不管你是win32 还是 win64 ，都是统一使用 win32
win32 {

    FFMPEG_HOME = ../ffmpeg-6.0-full_build-shared
    SDL_HOME = ../SDL2-devel-2.0.14-mingw/SDL2-2.0.14/x86_64-w64-mingw32


#INCLUDEPATH += 的意思是再原先的INCLUDEPATH的基础上，再添加等号后面的值 $${SDL_HOME}的意思是从 SDL_HOME中取出值，也就是 ../sdl,
#连起来看，这句话的意思是，给原先的  INCLUDEPATH ，再加上 当前.pro文件的上一级目录下的/sdl/include
#INCLUDEPATH 的意思是添加 .h文件
INCLUDEPATH += $${SDL_HOME}/include/SDL2 \
            $${FFMPEG_HOME}/include


#LIBS 的意思是添加静态库和动态库的访问路径，
LIBS += -L$${SDL_HOME}/lib \
        -L$${FFMPEG_HOME}/lib \
            -lavcodec \
            -lavdevice \
            -lavfilter \
            -lavformat \
            -lavutil \
            -lpostproc \
            -lswscale \
            -lswresample \
            -lsdl2


# message()可以用来打印
message(11111111111)
message($${SDL_HOME})
message($${FFMPEG_HOME})
message($$(PATH))
}


mac {
    FFMPEG_HOME = /usr/local/Cellar/ffmpeg/4.3.2
    SDL_HOME = /usr/local/Cellar/SDL2-devel-2.0.14-mingw/SDL2-2.0.14/

    INCLUDEPATH += $${SDL_HOME}/include/SDL2 \
            $${FFMPEG_HOME}/include


    #LIBS 的意思是添加静态库和动态库的访问路径，
    LIBS += -L$${SDL_HOME}/lib \
            -L$${FFMPEG_HOME}/lib \
                -lavcodec \
                -lavdevice \
                -lavfilter \
                -lavformat \
                -lavutil \
                -lpostproc \
                -lswscale \
                -lswresample \
                -lsdl2
}

# 库文件路径
#mac:INCLUDEPATH += $${FFMPEG_HOME}/include

# 需要链接哪些库？默认是链接动态库
#mac:LIBS += -L $${FFMPEG_HOME}/lib \

message()方法可以在.pro文件中 打印相关信息

# message()可以用来打印
message(11111111111)
message($${SDL_HOME})
message($${FFMPEG_HOME})
message($$(PATH))

可以看到message 打印相关的信息 是在 QT 的 “概要信息” 中的。

我们将信息分析如下：

Project MESSAGE: 11111111111
Project MESSAGE: ../SDL2-devel-2.0.14-mingw/SDL2-2.0.14/x86_64-w64-mingw32
Project MESSAGE: ../ffmpeg-6.0-full_build-shared

/// PATH 信息,前三行为QT 安装的path，下来是 系统变量， 最后三行是Anminister的用户变量
Project MESSAGE: C:\Qt\Qt5.14.2\Tools\mingw730_64\bin;
C:\Qt\Qt5.14.2\5.14.2\mingw73_64\bin;
C:\Qt\Qt5.14.2\Tools\mingw730_64\bin;


D:\Ctool\ffmpeg-4.2.1-win32-shared\bin;
C:\Program Files (x86)\VMware\VMware Workstation\bin\;
D:\Ctool\yinshipin\ffmpeg-6.0-full_build-shared\bin;
C:\Program Files\Microsoft MPI\Bin\;
C:\Program Files (x86)\Common Files\Oracle\Java\javapath;
C:\windows\system32;
C:\windows;
C:\windows\System32\Wbem;
C:\windows\System32\WindowsPowerShell\v1.0\;
C:\windows\System32\OpenSSH\;
C:\Program Files\dotnet\;
C:\Program Files\Microsoft SQL Server\130\Tools\Binn\;
C:\Program Files\IDM Computer Solutions\UltraEdit;
C:\Program Files\Git\cmd;
C:\Program Files\TortoiseGit\bin;
D:\Ctool\SDL2-devel-2.0.14-mingw\SDL2-2.0.14\x86_64-w64-mingw32\bin;
D:\Ctool\x86_64-8.1.0-release-win32-seh-rt_v6-rev0\mingw64\bin;
C:\Program Files\CMake\bin;
D:\Ctool\protobuf\protobuf-windows\bin;
D:\Ctool\protobuf\protobuf-windows\lib;
C:\Program Files\Java\jdk1.8.0_241\bin;
C:\Program Files\Microsoft VS Code\bin;
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.16.27023\bin\Hostx64\x64;
D:\Ctool\SDL2-devel-2.0.14-mingw\SDL2-2.0.14\x86_64-w64-mingw32\bin;
C:\Program Files\OpenSSL-Win64\bin;

C:\Users\Administrator\AppData\Local\Microsoft\WindowsApps;
C:\Users\Administrator\.dotnet\tools;
C:\Program Files\JetBrains\CLion 2023.3.4\bin;

3.注意的问题

我们在这里 加载了 ffmpeg 库，加载了sdl的库，要注意的是：在加载多个第三方库的时候，INCLUDEPATH，LIBS时，只能写一个，不能写多个，否则build fail。 

INCLUDEPATH += $${SDL_HOME}/include/SDL2 \
            $${FFMPEG_HOME}/include


    #LIBS 的意思是添加静态库和动态库的访问路径，
    LIBS += -L$${SDL_HOME}/lib \
            -L$${FFMPEG_HOME}/lib \
                -lavcodec \
                -lavdevice \
                -lavfilter \
                -lavformat \
                -lavutil \
                -lpostproc \
                -lswscale \
                -lswresample \
                -lsdl2