概述：

Android NDK是一系列工具的集合。幫助開發者快速開發C（或C++）的動態庫，並能自動將so和java應用一起打包成apk。NDK集成了交叉編譯器，並提供了相應的mk檔案隔離平臺、CPU、API等差異，開發人員只需要簡單修改mk檔案（指出“哪些檔案需要編譯”、“編譯特性要求”等），就可以創建出so。NDK可以自動地將so和Java應用一起打包，極大地減輕了開發人員的打包工作。

http://dl.google.com/android/ndk/android-ndk-r7-windows.zip

建立目錄jni，比如F:\NDK-Build\jni，要編譯的C/C++程式碼在該目錄的外層（即F:\ClientSocketEngine

jni目錄下為mk檔案

其中Android.mk檔案如下

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_MODULE := u3dtools_shared
LOCAL_MODULE_FILENAME := libu3dtools

# 配置自己的原始檔目錄和原始檔字尾名
MY_FILES_PATH  :=  $(LOCAL_PATH) \
                   $(LOCAL_PATH)/../../ClientSocketEngine

MY_FILES_SUFFIX := %.cpp %.c

# 遞迴遍歷目錄下的所有的檔案
rwildcard=$(wildcard $1$2) $(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2))

# 獲取相應的原始檔
MY_ALL_FILES := $(foreach src_path,$(MY_FILES_PATH), $(call rwildcard,$(src_path),*.*) ) 
MY_ALL_FILES := $(MY_ALL_FILES:$(MY_CPP_PATH)/./%=$(MY_CPP_PATH)%)
MY_SRC_LIST  := $(filter $(MY_FILES_SUFFIX),$(MY_ALL_FILES)) 
MY_SRC_LIST  := $(MY_SRC_LIST:$(LOCAL_PATH)/%=%)

# 去除字串的重複單詞
define uniq =
  $(eval seen :=)
  $(foreach _,$1,$(if $(filter $_,${seen}),,$(eval seen += $_)))
  ${seen}
endef

# 遞迴遍歷獲取所有目錄
MY_ALL_DIRS := $(dir $(foreach src_path,$(MY_FILES_PATH), $(call rwildcard,$(src_path),*/) ) )
MY_ALL_DIRS := $(call uniq,$(MY_ALL_DIRS))

# 賦值給NDK編譯系統
LOCAL_SRC_FILES  := $(MY_SRC_LIST)
#LOCAL_C_INCLUDES := $(MY_ALL_DIRS)

LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../ClientSocketEngine

include $(BUILD_SHARED_LIBRARY)
 

APP_STL := gnustl_static
APP_CPPFLAGS := -frtti -DCOCOS2D_DEBUG=1 -fexceptions

@set "NDK_ROOT=E:/InstallPack/android-ndk-r9d"

@set "DIR=%cd%"
@REM ... use paths relative to current directory
@set "APP_ROOT=%DIR%/.."
@set "APP_ANDROID_ROOT=%DIR%"

@echo NDK_ROOT = %NDK_ROOT%
@echo APP_ROOT = %APP_ROOT%
@echo APP_ANDROID_ROOT = %APP_ANDROID_ROOT%

@echo Using prebuilt externals
@"%NDK_ROOT%/ndk-build.cmd" 
pause