前言
- 在新建的Lib中,As是没有
Native C++
项目的,需要自己手动建立 - 此方法在
Project
中也生效 - 环境
AS 3.5.2
,ndk 22.1.7171670
, 23的ndk有问题暂时没用
解决方案
-
设置ndk目录
步骤一
-
AS下载的没有
platforms
文件夹(没有文件夹,选中目录会报错),新建一个空白文件夹叫此名即可 -
项目切换到
image.pngProject
模式
-
在
image.pngmain
下新建cpp
-
可以新建一个
Native
项目,把CMakeLists.txt
和native-lib.cpp
移动出来,此处方便我直接贴出来
# 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).
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} )
#include <jni.h>
#include <string>
extern "C" JNIEXPORT jstring JNICALL
Java_com_blog_hooklibrary_jni_Query_stringFromJNI( //改名称
JNIEnv *env,
jobject /* this */) {
std::string hello = "Hello from C++";
return env->NewStringUTF(hello.c_str());
}
- 切回
Android
文件目录,找到Lib依赖
image.png
- 在
android{...}
下添加
externalNativeBuild {
cmake {
path "src/main/cpp/CMakeLists.txt" //根据自己的目录调整
version "3.10.2"
}
}
- java文件
public class Query {
static {
System.loadLibrary("native-lib");
}
public native String stringFromJNI();
}
-
最后,使用此方法
image.png
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