如何生成 .a 到 .so

Question

我拥有许多 .a 文件，并希望使用 ndk-build 生成 .so。

Android.mk

LOCAL_PATH  := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE := nonfree
LOCAL_MODULE += opencv_java3

LOCAL_SRC_FILES :=              \
    libopencv_aruco.a           \
    libopencv_bgsegm.a                  \
    libopencv_bioinspired.a     \
    libopencv_calib3d.a     \
    libopencv_ccalib.a     \
    libopencv_core.a     \
    libopencv_datasets.a     \
    libopencv_dnn.a     \
    libopencv_dpm.a     \
    libopencv_face.a     \
    libopencv_features2d.a     \
    libopencv_flann.a     \
    libopencv_fuzzy.a     \
    libopencv_highgui.a    \
    libopencv_imgcodecs.a    \
    libopencv_imgproc.a    \
    libopencv_line_descriptor.a    \
    libopencv_ml.a    \
    libopencv_objdetect.a    \
    libopencv_optflow.a    \
    libopencv_photo.a    \
    libopencv_plot.a    \
    libopencv_reg.a    \
    libopencv_rgbd.a    \
    libopencv_saliency.a    \
    libopencv_shape.a    \
    libopencv_stereo.a    \
    libopencv_stitching.a    \
    libopencv_structured_light.a    \
    libopencv_superres.a    \
    libopencv_surface_matching.a    \
    libopencv_text.a    \
    libopencv_tracking.a    \
    libopencv_ts.a    \
    libopencv_video.a    \
    libopencv_videoio.a    \
    libopencv_videostab.a   \
    libopencv_xfeatures2d.a   \
    libopencv_ximgproc.a   \
    libopencv_xobjdetect.a   \
    libopencv_xphoto.a

LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include

include $(PREBUILT_STATIC_LIBRARY)

要使用 NDK 构建，请使用这些 steps。

当试图生成 .so 这返回我这个错误：

C:\Android\sdk\ndk-bundle\build\ndk-build.cmd 清理 Android NDK： jni/Android.mk 中的 LOCAL_MODULE 定义不能包含空格
C:/Android/sdk/ndk-bundle/build//../build/core/build-shared-library.mk:23: *** Android NDK：请更正错误。中止。停下来。

进程以退出代码 2 结束

Answer 1

LOCAL_MODULE 指定最终构建的 .so 文件的名称。 由于 space is introduced in the name when you concatenate the two strings nonfree 和 opencv_java3 导致 ndk-build 出现错误：

LOCAL_MODULE := nonfree
LOCAL_MODULE += opencv_java3

如果您想要一个串联的名称，我建议您手动执行此操作：

LOCAL_MODULE := nonfree_opencv_java3

然后，您需要在通过 JNI 加载 .so 文件时指定此名称。