用于android ndk的opencv的Android Studio,找不到opencv头文件

我正在开发用于Android OpenCV开发的Android Studio,但是当我编译eclipse中的项目时,我遇到了这个错误：

D:\software\AndroidStudioProjects\CameraMe\openCVSamplefacedetection\src\main\jni\DetectionBasedTracker_jni.cpp:2:33: Fatal error: opencv2/core/core.hpp: No such file or directory

我想opencv的标题找不到,但我不知道出了什么问题.

Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

#OPENCV_CAMERA_MODULES:=off
#OPENCV_INSTALL_MODULES:=off
#OPENCV_LIB_TYPE:=SHARED
include D:\eclipse\OpenCV_2.4.9_android_sdk\sdk\native\jni\OpenCV.mk

LOCAL_SRC_FILES  := DetectionBasedTracker_jni.cpp
LOCAL_C_INCLUDES += $(LOCAL_PATH)
LOCAL_LDLIBS     += -llog -ldl

LOCAL_MODULE     := detection_based_tracker

include $(BUILD_SHARED_LIBRARY)

Application.mk

APP_STL := gnustl_static
APP_CPPFLAGS := -frtti -fexceptions
APP_ABI := armeabi-v7a
APP_PLATFORM := android-8

DetectionBasedTracker_jni.cpp

#include <DetectionBasedTracker_jni.h>
#include <opencv2/core/core.hpp>
#include <opencv2/contrib/detection_based_tracker.hpp>
......

解决方法:

当您使用Android Studio时,默认会忽略您的Makefile,并且即时生成新的Makefile,而不会正确引用OpenCV,因为它不受支持.

这就是NDK构建目前在Android Studio中运行的方式,并且它已被弃用,而更好的方法是在工作中.

您可以通过在build.gradle中执行此操作来取消激活此内置NDK支持并改为使用Makefile：

import org.apache.tools.ant.taskdefs.condition.Os

apply plugin: 'com.android.application'

android {
    ...

    sourceSets.main {
        jniLibs.srcDir 'src/main/libs' //set .so files directory to libs
        jni.srcDirs = [] //disable automatic ndk-build call
    }

    // call regular ndk-build(.cmd) script from app directory
    task ndkBuild(type: Exec) {
        if (Os.isFamily(Os.FAMILY_WINDOWS)) {
            commandLine 'ndk-build.cmd', '-C', file('src/main').absolutePath
        } else {
            commandLine 'ndk-build', '-C', file('src/main').absolutePath
        }
    }

    tasks.withType(JavaCompile) {
        compileTask -> compileTask.dependsOn ndkBuild
    }
}

顺便说一句,我看到你只将APP_ABI设置为armeabi-v7a,但OpenCV也支持x86和mips,因此您也可以轻松扩展对这些平台的支持.