Android NDK 開發(筆記一)

接引：Android NDK r7以上集成了cywin，在開發NDK時不用那麼麻煩的在去下載與配置cywin.

Android NDK 開發步驟：

Eclipse 首先配置Ndk路徑，Windows –>Preferences –>Android –>NDK ,指定NDK路徑：如：D:\AndroidNDK\ndk-r10e

如果在Windows – Preferences –>Android下沒有看到NDK配置選項，那麼請下載Eclipse–NDK插件，下載地址：http://pan.baidu.com/s/1dDXBKTN ，我是Win7 x64系統，所以請根據自己系統去下載相應的EclipseNdk插件。下載完成請將下載的xxxxxxxxxxxxndk.jar,拷貝，放到Eclipse根目錄，如：D:\Androiddevelop\eclipse\plugins文件下，重啟Eclipse就能看到了。

新建Android project 取名，AndroidNDKDemo,新建包名com.jni,新建JNI.java,在JNI中聲明需要調用的C方法。

選擇工程，右鍵選擇 Android Tools –>Add Native Support…，建立取名為hello-jni.so的so庫。點擊 Finish。

這時你會發現在工程目錄下，多出了一個jni目錄與obj目錄，目錄中有兩個文件分別是：Android.mk,與一個 hello.cpp文件。我這裡直接將hello.cpp文件換成hello.c文件了。

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根據生成的.h文件編譯相關的hello.c文件。

如果需要針對不同cpu生成不同規龔ky"/kf/web/php/" target="_blank" class="keylink">PHPwrXEbGliaGVsbG8uc2/U8tDo0qrU2mhlbGxvLmPOxLz+1tC9+NDQxdC2zzwvcD4NCjxwPmhlbGxvLmM8L3A+DQo8cHJlIGNsYXNzPQ=="brush:java;"> jstring Java_com_patch_JNI_Hello(JNIEnv* env, jobject obj) { #if defined(__arm__) #if defined(__ARM_ARCH_7A__) #if defined(__ARM_NEON__) #if defined(__ARM_PCS_VFP) #define ABI "armeabi-v7a/NEON (hard-float)" #else #define ABI "armeabi-v7a/NEON" #endif #else #if defined(__ARM_PCS_VFP) #define ABI "armeabi-v7a (hard-float)" #else #define ABI "armeabi-v7a" #endif #endif #else #define ABI "armeabi" #endif #elif defined(__i386__) #define ABI "x86" #elif defined(__x86_64__) #define ABI "x86_64" #elif defined(__mips64) /* mips64el-* toolchain defines __mips__ too */ #define ABI "mips64" #elif defined(__mips__) #define ABI "mips" #elif defined(__aarch64__) #define ABI "arm64-v8a" #else #define ABI "unknown" #endif return (*env)->NewStringUTF(env, "Yes ,Hello from JNI !");

}

Android.mk

    # Copyright (C) 2009 The Android Open Source Project
    #
    # Licensed under the Apache License, Version 2.0 (the "License");
    # you may not use this file except in compliance with the License.
    # You may obtain a copy of the License at
    #
    #      http://www.apache.org/licenses/LICENSE-2.0
    #
    # Unless required by applicable law or agreed to in writing, software
    # distributed under the License is distributed on an "AS IS" BASIS,
    # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    # See the License for the specific language governing permissions and
    # limitations under the License.
    #
    LOCAL_PATH := $(call my-dir)

    include $(CLEAR_VARS)

    LOCAL_MODULE    := hello-jni
    LOCAL_SRC_FILES := hello.c

    include $(BUILD_SHARED_LIBRARY)

Application.mk

內容：

    APP_ABI := all

Activity中調用：

運行一下，如果編譯成功你會發現libs目錄結構發生了變化

效果: