cmakelist 库依赖库_androidstudio cmakelist编译.cpp并且引用第三方库

一、项目结构

项目配置

主要是里面cmake的配置，ndk配置，设置cMakeLists.txt

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目录结构

.cpp文件和它需要的.h文件都放在cpp文件夹下

.cpp文件依赖的.so文件则放在jniLibs文件夹下，jniLibs文件夹在Gradle脚本中是默认存放.so文件的位置，如果你想改它则需要在build.gradle中指定它的位置，如下设置:

sourceSets {

main {

jniLibs.srcDirs = ['libs']

}

}

build.gradle设置

apply plugin: 'com.android.application'

android {

compileSdkVersion 26

defaultConfig {

applicationId "com.example.dell.dualcampreview"

minSdkVersion 15

targetSdkVersion 26

versionCode 1

versionName "1.0"

testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

externalNativeBuild {

cmake {

cppFlags "-frtti -fexceptions"

}

}

ndk {

abiFilters 'armeabi-v7a'

}

}

buildTypes {

release {

minifyEnabled false

proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

}

}

externalNativeBuild {

cmake {

path "CMakeLists.txt"

}

}

}

dependencies {

implementation fileTree(dir: 'libs', include: ['*.jar'])

implementation 'com.android.support:appcompat-v7:26.1.0'

implementation 'com.android.support.constraint:constraint-layout:1.0.2'

testImplementation 'junit:junit:4.12'

androidTestImplementation 'com.android.support.test:runner:1.0.1'

androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

}

二、CMakeLists.txt中的设置

整体都是系统自动生成 的，只看关键的几个地方

add_library()总共有三个

第一个是根据.cpp文件编译.so，如果有include的头文件的话，在后面加上include_directories()

第二个和第三个则是前面.cpp文件所需要的依赖的库文件，在后面需要加上set_target_properties()来它依赖的.so文件

末尾的 target_link_libraries，把前面的引入的库名都写上即可

# For more information about using CMake with Android Studio, read the

# documentation: https://d.android.com/studio/projects/add-native-code.html

# Sets the minimum version of CMake required to build the native library.

cmake_minimum_required(VERSION 3.4.1)

# Creates and names a library, sets it as either STATIC

# or SHARED, and provides the relative paths to its source code.

# You can define multiple libraries, and CMake builds them for you.

# Gradle automatically packages shared libraries with your APK.

#此处可以通过多加几个addlibrary来针对多个cpp文件来生成多个.so文件

#它的用法跟Android.mk里的定义差不多

#需要留意，编译出来的文件放在\build\intermediates\cmake中,但是不用自己复制了，它会自动复制到

#jniLibs文件夹下

add_library(

jniSTDualCamPreview

SHARED

src/main/cpp/main.cpp

)

#include的文件夹

include_directories(jniSTDualCamPreview

${CMAKE_SOURCE_DIR}/src/main/cpp/include)

#两个预编译好的库

add_library(STdisp SHARED IMPORTED)

set_target_properties(STdisp PROPERTIES IMPORTED_LOCATION

${CMAKE_SOURCE_DIR}/src/main/jniLibs/${ANDROID_ABI}/libSTdisp.so)

add_library(Stereoblur SHARED IMPORTED)

set_target_properties(Stereoblur PROPERTIES IMPORTED_LOCATION

${CMAKE_SOURCE_DIR}/src/main/jniLibs/${ANDROID_ABI}/libStereoblur.so)

# Searches for a specified prebuilt library and stores the path as a

# variable. Because CMake includes system libraries in the search path by

# default, you only need to specify the name of the public NDK library

# you want to add. CMake verifies that the library exists before

# completing its build.

find_library( # Sets the name of the path variable.

log-lib

# Specifies the name of the NDK library that

# you want CMake to locate.

log )

# Specifies libraries CMake should link to your target library. You

# can link multiple libraries, such as libraries you define in this

# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.

jniSTDualCamPreview

STdisp

Stereoblur

# Links the target library to the log library

# included in the NDK.

${log-lib} )

三、遇到的一个异常情况

1.编译.cpp正常，但是build生成apk的时候出的异常

> More than one file was found with OS independent path 'lib/armeabi-v7a/libmainLib.so'

处理方式

其实是因为自己把编译.cpp生成的.so复制到了jniLibs下，但是cMakeList它其实会自己去编译和复制，并且自动放到jniLibs下，所以最后打包的时候就会报错More than one file