使用 OpenCV for android 构建库在“未构建目标 XXX 因为没有构建命令”时失败答案

【问题标题】：Building Library with OpenCV for android fails on "not building target XXX because there was no build command for it"使用 OpenCV for android 构建库在“未构建目标 XXX 因为没有构建命令”时失败
【发布时间】：2017-04-06 06:12:54
【问题描述】：

我有一个使用 cmake 在 mac 上编译并且已经运行的工作 c++ 库。我现在正在尝试使用 Android Studio 和 gradle 为 Android 编译它。
当我尝试使用 Android Studio 编译它时，我收到了一个神秘的链接器错误，所以我尝试使用 gradle 包装器在命令行中编译它，然后出现以下错误：

externalNativeBuildRelease: not building target opencv_calib3d because there was no build command for it
externalNativeBuildRelease: not building target opencv_core because there was no build command for it
externalNativeBuildRelease: not building target opencv_features2d because there was no build command for it
externalNativeBuildRelease: not building target opencv_flann because there was no build command for it
externalNativeBuildRelease: not building target opencv_highgui because there was no build command for it
externalNativeBuildRelease: not building target opencv_imgcodecs because there was no build command for it
externalNativeBuildRelease: not building target opencv_imgproc because there was no build command for it
externalNativeBuildRelease: not building target opencv_ml because there was no build command for it
externalNativeBuildRelease: not building target opencv_objdetect because there was no build command for it
externalNativeBuildRelease: not building target opencv_photo because there was no build command for it
externalNativeBuildRelease: not building target opencv_shape because there was no build command for it
externalNativeBuildRelease: not building target opencv_stitching because there was no build command for it
externalNativeBuildRelease: not building target opencv_superres because there was no build command for it
externalNativeBuildRelease: not building target opencv_video because there was no build command for it
externalNativeBuildRelease: not building target opencv_videoio because there was no build command for it
externalNativeBuildRelease: not building target opencv_videostab because there was no build command for it 
...

我找不到这个问题的解释。
我的 CMakelists.txt 包括以下行：

set (OpenCV_DIR /usr/local/Cellar/opencv3/HEAD-876c2c0_4/share/OpenCV)
set (CMAKE_MODULE_PATH /usr/local/Cellar/opencv3/HEAD-876c2c0_4/share/OpenCV)
find_package(OpenCV REQUIRED)

它似乎找到了它，但无法构建它。如果有人知道如何解决这个问题，我将不胜感激。

【问题讨论】：

标签： android c++ opencv gradle android-ndk

【解决方案1】：

我找到了答案我正在使用为 macos 编译的 opencv 二进制文件我从这里下载了 android sdk https://sourceforge.net/projects/opencvlibrary/files/opencv-android/

它似乎有效

【讨论】：