Android NDK调用具有不同名称空间的本机方法 [英] Android NDK calling native method with different namespace

问题描述

我是JNI编程的新手 我可以像调用其他JNI名称空间定义一样调用本机方法吗?

i'm new from JNI programming Can i call a native method like from a different JNI namespace definition?

例如:

package com.example.hellojni;
public class HelloJni extends Activity
{
  public native int MyMethod();  
  public native int OtherMethod();   // this works have the namespace package=jniexport interface

  static {System.loadLibrary("hello-jni");}

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);

    int b = OtherMethod(); //works
    int a = MyMethod(); //ERROR java.lang.reflect.InvocationTargetException 
 }
}

   ================File.c================
    JNIEXPORT int JNICALL Java_Cardioline_HelloJni_MyMethod(JNIEnv *env, jobject thisObj) 
  {
return 1;
  }
   JNIEXPORT int JNICALL Java_com_example_hellojni_HelloJni_OtherMethod(JNIEnv *env, jobject thisObj)
 {
 return 2;
  }

推荐答案

否，JNI方法名称由javah预先确定.尝试从这里开始:

No, the JNI method name is predetermined by javah. Try starting here:

http://blog.edwards-research.com/2012/04/tutorial-android-jni/

javah将为您提供标头，并且您必须将方法声明复制到.c文件中.

javah will provide you with the header and you must copy the method declarations into your .c file.

如果要调用的另一个类中有JNI方法，请在Java中调用另一个类.基本上改变这个:

If you have a JNI method in another class that you want to call, call the other class in java. Basically change this:

int a = MyMethod();

对此:

int a = new CardioLine.HelloJni().MyMethod();

通常，我具有Java文件到.c/.cpp文件的一对一映射.这可能也是您想要的(对于具有本地方法的Java类).

Typically, I have a one-to-one mapping of Java files to .c/.cpp files. That's probably what you want too (for Java classes with native methods).

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