NDK编写C/C++基本流程

gistfile1.md

NDK编写C/C++基本流程

step one - make java class

src/com/rect/ndktest/NDKTest.java

package com.rect.ndktest;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class NDKTest extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_ndktest);
		TextView  myTextView = new TextView(this);  
		myTextView.setText( stringNDKTest() );  
		setContentView(myTextView); 
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.ndktest, menu);
		return true;
	}

	public native String  stringNDKTest();  
	public native String  stringNDKTest2();  

	static {  
		System.loadLibrary("NDKTest");  
	}  

}

step two - NDK 编写C/C++ 命令行格式 生成H头文件

javah -classpath src -d jni com.rect.ndktest.NDKTest

javah - java JDK tool

-classpaht src - java class path

-d jni - 生成路径

com.rect.ndktest.NDKTest - 生成的H文件

step three - 根据H头文件编写C++类

NDKTest.c

    #include <string.h>  
    #include <jni.h>  
    #include <stdio.h>  
    jstring  
    Java_com_rect_ndktest_NDKTest_stringNDKTest( JNIEnv* env,  
                                                      jobject thiz )  
    {  
        return (*env)->NewStringUTF(env, "Hello Test NDK !");  
    }  
    
    jstring  
    Java_com_rect_ndktest_NDKTest_stringNDKTest2( JNIEnv* env,  
                                                      jobject thiz )  
    {  
    		printf("hello my good day");
        return (*env)->NewStringUTF(env, "Hello Test NDK 222 !");  
    }  

step four - make the android.mk file

    LOCAL_PATH := $(call my-dir)
    include $(CLEAR_VARS)
    LOCAL_ARM_MODE := arm
    LOCAL_MODULE := NDKTest
    LOCAL_SRC_FILES := NDKTest.c
    include $(BUILD_SHARED_LIBRARY)