如何将本机库加载到本机android代码中? (AndroidStudio) [英] How to load native library into native android code? (AndroidStudio)

问题描述

我在C文件夹中有一个名为 mylib 的库 jniLibs/your_architecture/mylib.so

I have a library in C called mylib in the folder jniLibs/your_architecture/mylib.so

在Java中，要加载库，只需在源代码中键入该代码即可:

In Java, to load the library, you just have to type that code in your source:

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

但是如何在本机C代码中加载库(在Android Studio中)? 我补充说该库不使用JNI约定，它是一个普通的共享库.

But how can you load the library in a native C code (in Android Studio) ? I add that the library don't use the JNI conventions, it's a normal shared library.

推荐答案

如果这可以帮助某人，那么如何在本机代码c/c ++中加载库:

If this can help someone, here how to load a library in native code c/c++ :

1-以避免java.lang.UnsatisfiedLinkError: dlopen failed:将此添加到build.gradle到android块中:

1 - to avoid java.lang.UnsatisfiedLinkError: dlopen failed: add this to the build.gradle into android block :

sourceSets {
    main {
        jniLibs.srcDirs = ['src/main/jniLibs']
    }
}

假设您的lib文件位于

Assuming that your lib files are in

src/main/jniLibs/{Architecture}/

src/main/jniLibs/{Architecture}/

(取决于您的jniLibs文件夹在哪里，在我的情况下，它位于app/src/main/，但大多数时候在app/中)

( depending where is your jniLibs folder, in my case it is located at app/src/main/ but the most time it is in app/)

2-在您的CMakeList中，通过添加以下块将您的库添加为 SHARED 和 IMPORTED :

2 - In your CMakeList, add you library as SHARED and IMPORTED by adding the following block :

add_library(mylib SHARED
            IMPORTED
            )

---

3-通过添加以下代码段，添加目标属性以找到您的lib mylib.so :

---

3 - Add target properties to locate you lib mylib.so by adding the following block :

set_target_properties( mylib PROPERTIES 
IMPORTED_LOCATION 
${PROJECT_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/mylib.so
)

我们在此处后退(/../)，因为我们认为CMakeLists.txt位于

We back forward (/../) here because we concidere that CMakeLists.txt is in

src/main/cpp/

src/main/cpp/

否则，大多数时间是在app/文件夹中，在这种情况下，我们不需要后退.

Otherwise, the most time it is in app/ folder, in this case, we don't need to back forward.

所以我们必须先回到 main/，然后再进入 jniLibs/

So we have to back to main/ before going into jniLibs/

4-将您的lib mylib 添加到目标链接库:

4 - Add you lib mylib to your target link libraries :

target_link_libraries(native-library-jni
                      ..
                      ..
                      mylib
                      ..
                      ..
                      )

---

5-最后，要调用lib mylib.so 中的方法，您必须创建/复制粘贴包含这些方法签名的标头，并将其包含在源文件中: #include "mylib.h"

---

5 - Finally, to call methods of your lib mylib.so, you have to create/copy-past the header containing these methods signatures and include it in your source file : #include "mylib.h"

您现在可以调用方法[namespace::]method(args...)

---

其他链接:

PROJECT_SOURCE_DIR

CMAKE_SOURCE_DIR

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