Android-JNI-互调问题

问题1.返回String.

如果返回的是String,并且文件是c,不是cpp.

则需要(*env)->NewStringUTF(env,str)

JNIEXPORT jint JNICALL Java_test_test_test_ccx_com_testtesttest_Java2C_sort
  (JNIEnv *env, jobject instance, jint a, jint b ){

         jclass myclass = (*env)->FindClass(env,"test/test/test/ccx/com/testtesttest/Java2C");
         jmethodID mid = (*env)->GetMethodID(env,myclass,"show","(Ljava/lang/String;)V");
         (*env)->CallVoidMethod(env,instance,mid,(*env)->NewStringUTF(env,"adfsdvf"));

         return sort(a,b);
}

int sort(int a,int b ){
  return a+b;
}

 否则会报错.

    public native int sort( int a, int b);


    public void show(String msg) {
        Toast.makeText(mContext, msg, Toast.LENGTH_SHORT).show();
    }