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我想在我的项目中使用 android NDK。所以我的问题是，如何从 android NDK 集成和执行 hello-jni 的默认示例项目？请为我提供逐步解决方案...我对此一无所知...

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4 回答 4

5 
1.    First Create Android Project 
2.    Then Create Folder  in the Project with name jni (Dont use other name)

3.       Create File With the Android.mk ( Rightclick on the jni folder ->New -> File -                                                                                 >Android.mk)
// Coding To Build Path and Access
LOCAL_PATH :=$(call my-dir)         // This is Common
include $(CLEAR_VARS)               // This is common`enter code here`
LOCAL_MODULE    := myCFile  // myCFile is ur own  Name of the module
                that will be    called in Activity)
LOCAL_SRC_FILES := my.c   // Our C File What should be given in C
                                                                             file creation

include $(BUILD_SHARED_LIBRARY)


4.    Create C File like above With ur own name with the extension .c (This file will be
                                                           used  in LOCAL_SRC_FILES )
                    C File Will Look Like this:
Note :
// Your Package name com.JniMyDemo Then Your Activity File and then the Function name for c file
So that I used jint(return value) 
(Java) its must
(com_JniDemo) is  Specified in Package name(com.JniDemo) we couldnt use . for package so 
we put underscore for c file )
(JniMyDemoActivity) Is my class

First two arguement is Important one others are our own variable for function //

Include two header file string.h,jni.h


#include "string.h"
#include "jni.h"

jint Java_com_JniMyDemo_JniMyDemoActivity_add(JNIEnv *env,jobject jobj,jint n1,jint n2)
{
jint a,b,c;
a=n1;
b=n2;
return (a+b);
}

5.  Then Call the The C File Like this 

// Activity Look like this 

public class JniMyDemoActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TextView txt    =new TextView(this);
        txt.setText(" "+add(100,100));
        setContentView(txt);
    }

    private native int add(int i,int j,int k);
    static
    {
        System.loadLibrary("myCFile");
    }
}  

6.      Then Compile the C File by 
    Starting Terminal (cmd prompt) Type the Project Path like ( cd  Project Path) and Enter
    Then type the          ( Ndk Location/ndk-build) it will automatically compile & ur jni             folder
7.   If it success means Start the Actvity  it will show the Result of Addition
于 2011-08-30T11:44:29.467 回答
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对于 NDK 初学者来说，这是一个相当不错的教程：NDK入门。

于 2011-07-08T12:54:51.590 回答
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您在这里有一个很棒的教程，解释了使用 NDK 所需的所有内容，如何创建函数以及如何使用它们，并且很容易遵循。http://marakana.com/s/introduction_to_ndk,1153/index.html，对不起我的英语，不是我的母语。

于 2012-07-08T20:18:54.290 回答
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学习它是记住事情的艰难方法。在您从developers.android.com 下载的Android NDK 中，您将拥有docs 文件夹，其中包含不同的文档，这些文档将清楚地告诉您应该如何以及何时使用NDK。尤其是完整地浏览OVERVIEW.HTML。 http://developer.android.com/sdk/ndk/index.html

我第一次使用NDK时就是这样做的。我强烈推荐这种方式..

如果您对什么是本机代码感到困惑 -> 它是您想要与 Android 应用程序一起使用的 C 或 C++ 或汇编代码。这被称为本机代码，因为它不是 Java 语言。

一切顺利。

于 2012-04-18T09:03:12.553 回答