NDK(15)在ndk代码中注册和注销native函数

 

　　转自:  http://www.cnblogs.com/canphp/archive/2012/11/13/2768937.html

 

C和C++注册native函数的方式大致上相同，下面给出具体的代码。

 

/* JNINativeMethod数组的定义在C和C++中都一样*/  
static JNINativeMethod gMethods[] = {  
    {  
        "jobjectProcess",  
        "(Lcom/example/hellojni/HelloJni$Student;Ljava/lang/Integer;)V",  
        (void*)jobjectProcess  
    }  
    /*被省略掉的代码*/  
};  
  
jint JNI_OnLoad(JavaVM* vm,void* reserved)  
{  
    JNIEnv* env = NULL;  
    jint result=-1;  
    if( (*vm)->GetEnv(vm,(void**)&env , JNI_VERSION_1_4) != JNI_OK)  
        return result;  
    jclass HelloJniClazz=(*env)->FindClass(env,"com/example/hellojni/HelloJni");  
    /* C */  
    jint r=(*env)->RegisterNatives(env, HelloJniClazz, gMethods, sizeof(gMethods) / sizeof(JNINativeMethod));  
    /* C++ */  
    r=AndroidRuntime::registerNativeMethods(env,"com/example/hellojni/HelloJni",gMethods,NELEM(gMethods));  
    /*或者env->RegisterNatives(HelloJniClazz, gMethods, sizeof(gMethods) / sizeof(JNINativeMethod));*/  
    if(0 == r)  
        //注册native函数成功  
    else  
        //注册native函数失败  
    return JNI_VERSION_1_4;  
}  
  
void JNI_OnUnload(JavaVM* vm,void* reserved)  
{  
    JNIEnv* env = NULL;  
    if( (*vm)->GetEnv(vm,(void**)&env , JNI_VERSION_1_4) != JNI_OK)  
        return;  
    jclass HelloJniClazz=(*env)->FindClass(env,"com/example/hellojni/HelloJni");  
    /* C */  
    jint r=(*env)->UnregisterNatives(env,HelloJniClazz);  
    /* C++ */  
    jint r= env->UnregisterNatives(HelloJniClazz)  
    if(r == 0)  
        //注销native函数成功  
    else  
        //注销native函数失败  
}