Android NDK項目中未定義的引用錯誤

我想將C++文件導入到我的android項目中。首先，我使用android studio創建了一個支持C++的項目。它提供了骨架項目結構。我用add_library方法通過CMakeLists.text文件加載我的文件。我可以成功加載我的C++文件並能夠在項目視圖中看到。當我試圖調用從mClient.cpp的方法我的家鄉 - lib.cpp裏，我得到了Android NDK項目中未定義的引用錯誤

未定義的引用爲「Hello（）」

錯誤。由於我沒有看到任何IDE警告，我可以說我的文件已成功加載。但它在編譯時不起作用。我也嘗試通過cmake加載add_executable，但它也會產生相同的錯誤。請讓我知道我的配置和設置中缺少什麼？我是NDK和CMake的新手。謝謝你的時間。

mClinet.cpp

#include "mClient.h" 

static int hello(){ 
    return 1; 
}

mClient.h

#ifdef __cplusplus 
extern "C" { 
#endif 

static int hello(); 

#ifdef __cplusplus 
} 
#endif 
#endif

這是我CMake.text文件。

# Sets the minimum version of CMake required to build the native 
# library. You should either keep the default value or only pass a 
# value of 3.4.0 or lower. 

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 it for you. 
# Gradle automatically packages shared libraries with your APK. 

# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wall -UNDEBUG") 

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). 
      # Associated headers in the same location as their source 
      # file are automatically included. 
      src/main/cpp/native-lib.cpp 
      src/main/cpp/mClient.cpp) 

# Searches for a specified prebuilt library and stores the path as a 
# variable. Because system libraries are included 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 the 
# build script, prebuilt third-party libraries, or system libraries. 

target_link_libraries(native-lib android log)

我想從我的家鄉 - lib.cpp致電問候（）

#include <jni.h> 
#include <string> 
#include "mClient.h" 

extern "C" 
jstring 
Java_com_zawmyohtet_hellondk_MainActivity_stringFromJNI(
     JNIEnv* env, 
     jobject /* this */) { 

    int myInt = hello(); 

    std::string hello = "Hello from C++"; 
    return env->NewStringUTF(hello.c_str()); 
}

來源

2016-09-23 Zaw Myo Htet

@Eichhörnchen如果外部「C」由於名稱改變而不存在，則JNI調用將不起作用，這是完全合法的。 –

刪除static。 static表示在其翻譯單元外部不能訪問某個功能。

來源

2016-09-23 20:32:08

謝謝，它的工作原理。 –

Android NDK項目中未定義的引用錯誤

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