使用Android Studio 2.2和CMake在Android中编译和使用ABI相关的可执行二进制文件

我正在通过CMake通过stable gradle（）测试新的Android Studio C/C++构建

在我的应用程序中，一个已经扎根的设备需要使用我在Android Studio中编译的ABI依赖的二进制文件

当我试图用

add_library(mylib SHARED mylib.c)

它会自动编译并复制到APK的lib/[ABI]文件夹中（例如/lib/armeabi/mylib.so），但如果我使用以下命令编译可执行二进制文件：

add_executable(mybinary mybinary.cpp)

二进制文件在生成文件夹中正确生成：

app/build/intermediates/cmake/debug/lib/armeabi/mybinary
app/build/intermediates/cmake/debug/lib/x86_64/mybinary 
...

但它们似乎没有被复制到apk的任何地方

处理这种需求的正确方法是什么？一个渐进式的任务是一条路吗

build.gradle：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.1"
    defaultConfig {
        applicationId "com.my.app"
        minSdkVersion 10
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags ""
            }
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    externalNativeBuild{
        cmake{
            path "CMakeLists.txt"
        }
    }

    defaultConfig {
        externalNativeBuild {
            cmake {
                targets "
                arguments "-DANDROID_TOOLCHAIN=clang", "-DANDROID_PLATFORM=android-21"
                cFlags "-DTEST_C_FLAG1", "-DTEST_C_FLAG2"
                cppFlags "-DTEST_CPP_FLAG2", "-DTEST_CPP_FLAG2"
                abiFilters 'x86', 'x86_64', 'armeabi', 'armeabi-v7a'
            }
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.1.1'
    compile 'com.android.support:design:24.1.1'
    compile 'com.android.support:recyclerview-v7:24.1.1'
    compile 'eu.chainfire:libsuperuser:1.0.0.201607041850'
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_VERBOSE_MAKEFILE on)

add_executable(mybinary ${CMAKE_CURRENT_SOURCE_DIR}/mybinary.cpp)
target_link_libraries( mybinary libcustom)
target_include_directories (mybinary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

mybinary.cpp

#include <stdlib.h>
#include <string>
#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {

    string hello = "Hello from C++";
    cout << "Message from native code: " << hello << "\n";

    return EXIT_SUCCESS;
}

---

好的，我已经找到了一个解决方案，看起来很舒服，但可能有更合适的方法

默认情况下，CMakeLists.txt放在myAppProject/app中，因此我在CMakeLists.txt中添加了这一行：

set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_VERBOSE_MAKEFILE on)

# set binary output folder to Android assets folder
set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

add_subdirectory (src/main/cpp/mylib)
add_subdirectory (src/main/cpp/mybinary)

add_executable(mybinary ${CMAKE_CURRENT_SOURCE_DIR}/mybinary.cpp)
# mybinary, in this example, has mylib as dependency
target_link_libraries( mybinary mylib)
target_include_directories (mybinary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

add_library( # Sets the name of the library.
             mylib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             ${CMAKE_CURRENT_SOURCE_DIR}/mylib.cpp )

target_include_directories (mylib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

完整的应用程序/CMakeLists.txt：

set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_VERBOSE_MAKEFILE on)

# set binary output folder to Android assets folder
set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

add_subdirectory (src/main/cpp/mylib)
add_subdirectory (src/main/cpp/mybinary)

add_executable(mybinary ${CMAKE_CURRENT_SOURCE_DIR}/mybinary.cpp)
# mybinary, in this example, has mylib as dependency
target_link_libraries( mybinary mylib)
target_include_directories (mybinary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

add_library( # Sets the name of the library.
             mylib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             ${CMAKE_CURRENT_SOURCE_DIR}/mylib.cpp )

target_include_directories (mylib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

完整的app/src/main/cpp/mybinary/CMakeLists.txt：

set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_VERBOSE_MAKEFILE on)

# set binary output folder to Android assets folder
set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

add_subdirectory (src/main/cpp/mylib)
add_subdirectory (src/main/cpp/mybinary)

add_executable(mybinary ${CMAKE_CURRENT_SOURCE_DIR}/mybinary.cpp)
# mybinary, in this example, has mylib as dependency
target_link_libraries( mybinary mylib)
target_include_directories (mybinary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

add_library( # Sets the name of the library.
             mylib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             ${CMAKE_CURRENT_SOURCE_DIR}/mylib.cpp )

target_include_directories (mylib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

完整的app/src/main/cpp/mylib/CMakeLists.txt：

set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_VERBOSE_MAKEFILE on)

# set binary output folder to Android assets folder
set(EXECUTABLE_OUTPUT_PATH      "${CMAKE_CURRENT_SOURCE_DIR}/src/main/assets/${ANDROID_ABI}")

add_subdirectory (src/main/cpp/mylib)
add_subdirectory (src/main/cpp/mybinary)

add_executable(mybinary ${CMAKE_CURRENT_SOURCE_DIR}/mybinary.cpp)
# mybinary, in this example, has mylib as dependency
target_link_libraries( mybinary mylib)
target_include_directories (mybinary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

add_library( # Sets the name of the library.
             mylib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             ${CMAKE_CURRENT_SOURCE_DIR}/mylib.cpp )

target_include_directories (mylib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

这样，任何可执行二进制文件都会直接编译到assets文件夹中，位于名为目标ABI的子文件夹中，例如：

assets/armeabi/mybinary
assets/x86_64/mybinary
... 

为了在应用程序中使用正确的二进制文件，应选择正确的二进制文件：

String abi;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    abi = Build.SUPPORTED_ABIS[0];
} else {
    //noinspection deprecation
    abi = Build.CPU_ABI;
}
String folder;
if (abi.contains("armeabi-v7a")) {
    folder = "armeabi-v7a";
} else if (abi.contains("x86_64")) {
    folder = "x86_64";
} else if (abi.contains("x86")) {
    folder = "x86";
} else if (abi.contains("armeabi")) {
    folder = "armeabi";
}
...
AssetManager assetManager = getAssets();
InputStream in = assetManager.open(folder+"/" + "mybinary");

然后，应使用正确的执行权限从资产文件夹中复制二进制文件：

OutputStream out = context.openFileOutput("mybinary", MODE_PRIVATE);
long size = 0;
int nRead;
while ((nRead = in.read(buff)) != -1) {
    out.write(buff, 0, nRead);
    size += nRead;
}
out.flush();
Log.d(TAG, "Copy success: " +  " + size + " bytes");
File execFile = new File(context.getFilesDir()+"/mybinary");
execFile.setExecutable(true);

就这些

更新： gradle.build文件：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25"
    defaultConfig {
        applicationId "com.myapp.example"
        minSdkVersion 10
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags ""
            }
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    externalNativeBuild {
        cmake {
            path "CMakeLists.txt"
        }
    }

    defaultConfig {
        externalNativeBuild {
            cmake {
                targets "mylib", "mybinary"
                arguments "-DANDROID_TOOLCHAIN=clang"
                cFlags "-DTEST_C_FLAG1", "-DTEST_C_FLAG2"
                cppFlags "-DTEST_CPP_FLAG2", "-DTEST_CPP_FLAG2"
                abiFilters 'armeabi', 'armeabi-v7a', 'x86', 'x86_64'
            }
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:25.0.0'
    compile 'com.android.support:design:25.0.0'
    compile 'com.android.support:recyclerview-v7:25.0.0'
    compile 'com.android.support:cardview-v7:25.0.0'
    compile 'eu.chainfire:libsuperuser:1.0.0.201607041850'
}

将可执行文件输出到Android Gradle插件需要库的地方：

设置（CMAKE_RUNTIME_output_DIRECTORY“${CMAKE_LIBRARY_output_DIRECTORY}”）

愚弄插件，使其认为您的可执行文件是共享对象：

添加可执行文件（i\u an_executable.so main.c）

检查APK:

$7z l构建/输出/APK/app-debug.APK lib/[2:08:56] $ 7z l build/outputs/apk/app-debug.apk lib/ [2:08:56] Date Time Attr Size Compressed Name ------------------- ----- ------------ ------------ ------------------------ ..... 9684 4889 lib/armeabi/i_am_an_executable.so ..... 6048 1710 lib/arm64-v8a/i_am_an_executable.so ..... 9688 4692 lib/armeabi-v7a/i_am_an_executable.so ..... 5484 1715 lib/x86/i_am_an_executable.so ..... 6160 1694 lib/x86_64/i_am_an_executable.so 日期时间属性大小压缩名称 ------------------- ----- ------------ ------------ ------------------------ ..... 9684 4889 lib/armeabi/i_am_an_executable.so ..... 6048 1710 lib/arm64-v8a/i_am_\u an_executable.so ..... 9688 4692 lib/armeabi-v7a/i_am_\u an_executable.so ..... 5484 1715 lib/x86/i_am__an_executable.so ..... 6160 1694 lib/x86_64/i_am_an_executable.so

访问并运行可执行文件；它位于

上下文.getApplicationInfo（）.nativeLibraryDir

中

---

这样做的缺点是，您无法将

android:extractNativeLibs

设置为

false

——我不知道从应用程序内部访问APK中的

lib/

。

这太好了。为什么要这样麻烦呢？对于共享库，机制已经存在，只需使用loadlibrary（）加载它并使用。我没有在我的资产文件夹中获得任何构建文件，只是创建了空目录。如果我没记错的话，前一段时间有一个Gradle更新给了我类似的问题；我已经用应用程序的build.gradle文件更新了答案，请特别注意“defaultConfig”部分。原来的gradle.build（作为整个项目）要复杂得多，所以我删掉了不必要的部分。无论如何，我已经再次更新了答案，以更好地反映我的实际CMakeLists配置。查看3个CMakeLists.txt文件。但是，您是否在gradle构建文件中显式设置了“目标”？我发布了一个示例代码：使用getResources（）.getAssets（）.OpenNoAssetFD（）打开嵌入的二进制文件，以便您自己提取它。不要强迫Android提取你的库。“添加可执行文件”不是用来创建命令行程序而不是共享库吗？为什么它被命名为“我是一个可执行文件，所以”