DllNotFoundException in NDK Android Application Using Xamarin

Question

I want to make an Android application that uses NDK with C ++

I made a new Android solution in Xamarin Studio called ndkTest. I added the jni folder and these files are added there:

• Android.mk
• Application.mk
• my.h
• test.cpp

Here are the contents of each of them:

Android.mk :

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := ndkTest
LOCAL_SRC_FILES := test.cpp
LOCAL_STATIC_LIBRARIES := my

include $(BUILD_SHARED_LIBRARY)

Application.mk :

APP_ABI := armeabi-v7a
APP_STL := stlport_static

my.h :

#ifndef __MY_H__
#define __MY_H__

#define MY_CONST    1

#ifdef __cplusplus
extern "C"
#endif
short
my_func( short          my_param );

#endif /* __MY_H__ */

test.cpp

// test.cpp
//

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>

#include <iostream>
#include <fstream>
#include <vector>

#include "my.h"

#define SOME_CONST     2*MY_CONST
short  some_short;

#ifdef __cplusplus
extern "C"
{
#endif

static void static_func_0()
{
some_short = 0;
}

static void static_func_1()
{
some_short = 1;
}

#ifdef __cplusplus
}
#endif

static void static_print()
{
printf("static_print\n");
printf("some_short = %d\n", some_short);
}

extern "C" short getSomeShort()
{
printf("myExtern\n");
return some_short;
}

---

Here, where it gets interesting: I have ndk installed and configured correctly. At the command prompt, I connected to the project directory and ran

ndk-build

And I get this error:

make.exe: *** No rule to make target [path to ndk]/sources/cxx-stl/stlport/test.cpp', needed byobj/local/armeabi/objs/ndkTest/test.o'. Stop.

This is strange, but I can specify the full path to test.cpp in Android.mk, and it creates:

[armeabi] Compile++ thumb: ndkTest <= test.cpp
[armeabi] SharedLibrary : libndkTest.so
[armeabi] Install : libndkTest.so => libs/armeabi/libndkTest.so

So now I have a .so file. After adding this to the beginning of MainActivity.cs: using System.Runtime.InteropServices;I added the following:

[DllImport("libndkTest", EntryPoint="getSomeShort")]
static extern short getSomeShort();

OnCreate. DllNotFoundException. ?

Answer 1

:

Xamarin Studio " ", "", " Android" "" ABI, armeabi-v7a. - Samsung S6, arm64-v8a, .

YMMV

Answer 2

, , libndkTest ndkTest DllImport.

[DllImport("ndkTest")]
static extern short getSomeShort();

, .

, , , lib/your_abi/your_lib.so. , 2 - ...