Android studio 2.2版本以后對C/C++的支持可以說很方便了，當然官方推薦使用Cmake完成對C/C++的支持

2.2版本以上的同學新建一個項目就知道了，步驟如下：

File -> New -> New PRoject,如下圖：

然后勾選Include C++ support,一直next ，最后Finish以后，項目就出現了，和一般的項目略有不同，其實只要多了幾個文件，而已：

1：目錄下多了個CmakeLists.txt文件

2：src目錄下多了一個cpp目錄，里面有個.cpp文件，C++文件都是以.cpp結尾的。

3：就是build.gradle內容中添加了幾行配置

一一解讀一下，先來看看CmakeLists.txt 文件里面的內容是什么：

# 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.add_library( # Sets the name of the library.             native-lib             # Sets the library as a shared library.             SHARED             # Provides a relative path to your source file(s).             src/main/cpp/native-lib.cpp )# 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.                       native-lib                       # Links the target library to the log library                       # included in the NDK.                       ${log-lib} )這里有設置Cmake版本啊，引用的cpp文件的路徑啊等等，如果自己引用的話 其實值需要修改引用的cpp路徑即可，
其他的暫時不需要動
看下native_lib.cpp文件內容：
#include <jni.h>#include <string>extern "C"JNIEXPORT jstring JNICALLjava_com_process_main_myapplication_MainActivity_stringFromJNI(        JNIEnv* env,        jobject /* this */) {    std::string hello = "Hello from C++";    return env->NewStringUTF(hello.c_str());}很簡單 其實就是輸出Hello from C++這段文字：
再看下build.gradle的配置改變：
apply plugin: 'com.android.application'android {    compileSdkVersion 25    buildToolsVersion "25.0.2"    defaultConfig {        applicationId "com.process.main.myapplication"        minSdkVersion 22        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"        }    }}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'    })    compile 'com.android.support:appcompat-v7:25.1.1'    compile 'com.android.support.constraint:constraint-layout:1.0.0-beta4'    testCompile 'junit:junit:4.12'}主要多了兩個地方的改變：
1：defaultConfig中添加：
externalNativeBuild {            cmake {                cppFlags ""            }        }2：在android{}中添加：
externalNativeBuild {    cmake {        path "CMakeLists.txt"    }}其實也就是引用CmakeLists.txt文件。
說到這里，大致知道C++項目的大致結構了。那么原始項目怎么添加C++呢，步驟如下：
1，現在src/main目錄下新建cpp目錄和java目錄同級，然后在cpp目錄中新建一個.cpp文件，這里以native-lib.cpp為例子直接copy進去
2，右鍵項目（選中項目，然后右鍵）如下：
選擇第二個Link C++  Project  with Gradle，出現以下界面：
關于Project Path是選擇CmakeLists.txt文件的路徑，這里先把之前的CmakeLists.txt文件直接copy過來，然后相應的修改即可：
選擇CmakeLists文件然后點擊OK按鈕。修改CmakeLists.txt文件中的cpp文件引用目錄即可(add_library {第三行})。
接下來，在java代碼中調用C++代碼啦，看下MainActivity中的代碼：
public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    // Example of a call to a native method    TextView tv = (TextView) findViewById(R.id.sample_text);    tv.setText(stringFromJNI());    }    /**     * A native method that is implemented by the 'native-lib' native library,     * which is packaged with this application.     */    public native String stringFromJNI();    // Used to load the 'native-lib' library on application startup.    static {        System.loadLibrary("native-lib");    }}這里注意System.loadLibrary("native-lib"),加載（native-lib）Library，這里是CmakeLists文件中配置好的Library名字要對應。
然后就是native調用stringFromJNI ()方法啦》
最后編譯一下app，Make Project  build一下，然后run到手機上就可以運行了。
這里有同學想問那.so文件在哪里找啊 ，如下圖：
這里的so文件就可以用到其他項目中啦；
至此一個簡單的使用C++項目就完成啦