## Android NDK: Could not find application project directory 记得前阵子编译so库直接使用ndk-build搞定，今天使用却报错如下： ~~~ $ ndk-build Android NDK: Could not find application project directory ! Android NDK: Please define the NDK_PROJECT_PATH variable to point to it. /opt/android-ndk-r10b/build/core/build-local.mk:148: *** Android NDK: Aborting . Stop. ~~~ 高人支招如下： ~~~ You need to specify 3 things. NDK_PROJECT_PATH - the location of your project NDK_APPLICATION_MK - the path of the Application.mk file APP_BUILD_SCRIPT - the path to the Android.mk file These are needed to override the default values of the build script, which expects things to be in the jni folder. When calling ndk-build use ndk-build NDK_PROJECT_PATH=/path/to/proj NDK_APPLICATION_MK=/path/to/Application.mk In Application.mk add APP_BUILD_SCRIPT := /path/to/Android.mk ~~~ 首先第一步，在Application中加入Android.mk路径  比如这两个文件是同级的: ~~~ APP_BUILD_SCRIPT := Android.mk ~~~ 第二步，直接编译： ~~~ $ ndk-build NDK_PROJECT_PATH=. NDK_APPLICATION_MK=Application.mk [armeabi-v7a] Compile++ thumb: detection_and_recognition_lib <= DetectionAndRecognition.cpp [armeabi-v7a] Prebuilt : libopencv_java.so <= /home/linc/workspace/lab/OpenCV-android-sdk-2.4.11/sdk/native/jni/../libs/armeabi-v7a/ [armeabi-v7a] SharedLibrary : libdetection_and_recognition_lib.so /opt/android-ndk-r10b/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: warning: hidden symbol '__aeabi_atexit' in /opt/android-ndk-r10b/sources/cxx-stl/gnu-libstdc++/4.6/libs/armeabi-v7a/thumb/libgnustl_static.a(atexit_arm.o) is referenced by DSO ./obj/local/armeabi-v7a/libopencv_java.so [armeabi-v7a] Install : libdetection_and_recognition_lib.so => libs/armeabi-v7a/libdetection_and_recognition_lib.so [armeabi-v7a] Prebuilt : libnative_camera_r4.3.0.so <= /home/linc/workspace/lab/OpenCV-android-sdk-2.4.11/sdk/native/jni/../libs/armeabi-v7a/ [armeabi-v7a] Install : libnative_camera_r4.3.0.so => libs/armeabi-v7a/libnative_camera_r4.3.0.so [armeabi-v7a] Prebuilt : libnative_camera_r4.4.0.so <= /home/linc/workspace/lab/OpenCV-android-sdk-2.4.11/sdk/native/jni/../libs/armeabi-v7a/ [armeabi-v7a] Install : libnative_camera_r4.4.0.so => libs/armeabi-v7a/libnative_camera_r4.4.0.so [armeabi-v7a] Install : libopencv_java.so => libs/armeabi-v7a/libopencv_java.so [x86] Compile++ : detection_and_recognition_lib <= DetectionAndRecognition.cpp [x86] Prebuilt : libopencv_java.so <= /home/linc/workspace/lab/OpenCV-android-sdk-2.4.11/sdk/native/jni/../libs/x86/ [x86] SharedLibrary : libdetection_and_recognition_lib.so [x86] Install : libdetection_and_recognition_lib.so => libs/x86/libdetection_and_recognition_lib.so [x86] Prebuilt : libnative_camera_r4.3.0.so <= /home/linc/workspace/lab/OpenCV-android-sdk-2.4.11/sdk/native/jni/../libs/x86/ [x86] Install : libnative_camera_r4.3.0.so => libs/x86/libnative_camera_r4.3.0.so [x86] Prebuilt : libnative_camera_r4.4.0.so <= /home/linc/workspace/lab/OpenCV-android-sdk-2.4.11/sdk/native/jni/../libs/x86/ [x86] Install : libnative_camera_r4.4.0.so => libs/x86/libnative_camera_r4.4.0.so [x86] Install : libopencv_java.so => libs/x86/libopencv_java.so ~~~ 各位大虾也许看出来了，我在编译OpenCV相关的项目。而现在的设备选型已经涵盖了x86架构，所以编译时要选择x86指令集编译。在Application.mk中注明如下： ~~~ APP_ABI := armeabi-v7a x86 ~~~ 后记：  放到jni目录下就不用此命令了！ > 参考：  > [http://stackoverflow.com/questions/14156596/ndk-cant-find-the-application-directory](http://stackoverflow.com/questions/14156596/ndk-cant-find-the-application-directory)