关于Android studio ndk的配置大家可以在网上找教程进行，这里不介绍了。

1.OpenCV下载及准备

下载地址：https://opencv.org/releases/

找到最新版本（当前最新4.5.3）的下载地址，点击Android进入下载

解压出如下文件夹

 2.下面开始建Android项目配置

 新建的项目自己带一个native-lib实例，可以测试跑一下

 修改要我们要支持的CPU架构下，后面会附完整build.gradle文件代码

 题外话：调用OpenCV4Android中的so动态库用于打包进APK，下图中红框内的路径就是我们上面下载的OpenCV4.1.0中的动态库路径（注意：现在已经不需要配置这个啦，会报错 2 files found with path 'lib/armeabi-v7a/libopencv_java4.so' from inputs:）

具体解释在https://developer.android.com/studio/releases/gradle-plugin#cmake-imported-targets

 3.完整build.gradle文件

plugins {
    id 'com.android.application'
}

android {
    compileSdk 30

    defaultConfig {
        applicationId "com.example.opencvdemo"
        minSdk 21
        targetSdk 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags ''
                abiFilters 'x86','armeabi-v7a'
                arguments "-DANDROID_ARM_NEON=TRUE",'-DANDROID_STL=c++_shared'
            }
        }
    }
//
//    sourceSets{
//        main{
//            //当前这个目录下的库文件会被调用并且被打包进apk中
//            jniLibs.srcDirs = ['D:/download/OpenCV-android-sdk/sdk/native/libs']
//        }
//    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    externalNativeBuild {
        cmake {
            path file('src/main/cpp/CMakeLists.txt')
            version '3.10.2'
        }
    }
    buildFeatures {
        viewBinding true
    }
}

dependencies {

    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'com.google.android.material:material:1.3.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
    testImplementation 'junit:junit:4.13.2'

}

4.修改CMakeLists.txt文件

# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html

# Sets the minimum version of CMake required to build the native library.

cmake_minimum_required(VERSION 3.10.2)
#project("OpenCVDemo")
# Declares and names the project.

#该变量为真时会创建完整版本的Makefile
set(CMAKE_VERBOSE_MAKEFILE on)
#定义变量ocvlibs使后面的命令可以使用定位具体的库文件
set(opencvlibs "D:/download/OpenCV-android-sdk/sdk/native/libs")
#调用头文件的具体路径
include_directories(D:/download/OpenCV-android-sdk/sdk/native/jni/include)

#增加我们的动态库
add_library(libopencv_java4 SHARED IMPORTED)
#建立链接
set_target_properties(libopencv_java4 PROPERTIES IMPORTED_LOCATION
        "${opencvlibs}/${ANDROID_ABI}/libopencv_java4.so")

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
        native-lib

        # Sets the library as a shared library.
        SHARED

        # Provides a relative path to your source file(s).
        native-lib.cpp)

# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
        log-lib

        # Specifies the name of the NDK library that
        # you want CMake to locate.
        log)

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
        native-lib libopencv_java4 jnigraphics

        # Links the target library to the log library
        # included in the NDK.
        ${log-lib})

 修改完后最好执行一下如下操作：

 执行完后切换到Android视图下会在cpp--includes下看到opencv2已导入

编译可能会报如下错误提示：

java.lang.UnsatisfiedLinkError: dlopen failed: library "libc++_shared.so" not found

这个解决办法已在上面提供的build.gradle文件中给出

 重新编译，成功！