NDK環境配置hello

1.新建一個空項目

 

 

2.新建一個java類以及方法聲明

 

package com.example.ndkdemo;

public class Hello {


    static {
        System.loadLibrary("hello");
    }

    public static native String sayHello();
}

 

3.gradle.properties中加入 

android.useDeprecateNdk=true

4.在Teeminal中javah生成com_example_ndktest_Hello.h,然後新建一個Hello.cpp文件

 

 

//
// Created by wanghuanlong on 2019/8/9.
//

#include "com_example_ndktest_Hello.h"

JNIEXPORT jstring JNICALL Java_com_example_ndktest_Hello_sayHello
  (JNIEnv * env, jclass jclass){

return env->NewStringUTF("hello C");
 }

 

ndk中配置

ndk{
    moduleName "hello" //模塊名，需要和System.loadLibrary("xxx");中的xxx保持一致，必現一致
    abiFilters "armeabi", "armeabi-v7a", "x86"//平臺支持，java是跨平臺語言，C語言不是，這裏添加的是支持的平臺，具體含義百度
}

 

CMakeLists.txt 文件

# 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.

		#庫文件名
        hello

        # Sets the library as a shared library.
        SHARED

        # Provides a relative path to your source file(s).
        #cpp文件
        Hello.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.
		#庫文件名
        hello

        # Links the target library to the log library
        # included in the NDK.
        ${log-lib})

在MainActivity中配置顯示在TextView上

 

運行結果