OpenCv with Android studio 1.3+ 使用新的 gradle - undefined reference

Question

我在使用本机 OpenCv 2.4.11（3.0.0 也可以）和 Android Studio 1.3+ 以及新的 ndk 支持时遇到问题。所有关于 .mk 文件的教程，但我想将它用于新的实验 gradle。
使用 Kiran 答案 OpenCV in Android Studio 我在 java 中工作得很好。我也改变了
gradle-wrapper.properties：

distributionUrl=https\://services.gradle.org/distributions/gradle-2.5-all.zip

build.gradle（申请）：

classpath 'com.android.tools.build:gradle-experimental:0.2.0'

build.gradle（模块）：

apply plugin: 'com.android.model.application'

model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.0"

        defaultConfig.with {
            applicationId = "android.overloaded.nativetestv4"
            minSdkVersion.apiLevel = 18
            targetSdkVersion.apiLevel = 23
            versionCode = 1
            versionName = "1.0"
        }
    }

    android.ndk{
        moduleName = "mymodule"
        ldLibs += ['log']
        cppFlags += "-std=c++11" 
        cppFlags += "-fexceptions"
        cppFlags  += "-I${file("C:/DevAndroid/OpenCV-android-sdk/sdk/native/jni/include")}".toString()
        cppFlags  += "-I${file("C:/DevAndroid/OpenCV-android-sdk/sdk/native/jni/include/opencv")}".toString()

        ldLibs += ["android", "EGL", "GLESv2", "dl", "log", "z"] //added z
        stl = "stlport_static"//"gnustl_shared" changed to stlport static
    }

    android.buildTypes {
        release {
            minifyEnabled = false
            proguardFiles += file('proguard-rules.pro')
        }
    }
    android.productFlavors { //added all productFlavors code
        create("arm") {
            ndk.with {
                abiFilters += "armeabi"
                File curDir = file('./')
                curDir = file(curDir.absolutePath)
                String libsDir = curDir.absolutePath+"\src\main\jniLibs\armeabi\" //"-L" +
                ldLibs += libsDir + "libnative_camera_r4.3.0.so"
                ldLibs += libsDir + "libopencv_contrib.a"
                ldLibs += libsDir + "libopencv_core.a"
                ldLibs += libsDir + "libopencv_highgui.a"
                ldLibs += libsDir + "libopencv_imgproc.a"
                ldLibs += libsDir + "libopencv_info.so"
                ldLibs += libsDir + "libopencv_java.so"
                ldLibs += libsDir + "libopencv_legacy.a"
                ldLibs += libsDir + "libopencv_ml.a"
                ldLibs += libsDir + "libopencv_ts.a"
            }
        }
        create("armv7") {
            ndk.with {
                abiFilters += "armeabi-v7a"
                File curDir = file('./')
                curDir = file(curDir.absolutePath)
                String libsDir = curDir.absolutePath+"\src\main\jniLibs\armeabi-v7a\" //"-L" +

               ldLibs += libsDir + "libnative_camera_r4.3.0.so"
               ldLibs += libsDir + "libopencv_contrib.a"
               ldLibs += libsDir + "libopencv_core.a"
               ldLibs += libsDir + "libopencv_highgui.a"
               ldLibs += libsDir + "libopencv_imgproc.a"
               ldLibs += libsDir + "libopencv_info.so"
               ldLibs += libsDir + "libopencv_java.so"
               ldLibs += libsDir + "libopencv_legacy.a"
               ldLibs += libsDir + "libopencv_ml.a"
               ldLibs += libsDir + "libopencv_ts.a"
            }
         }
         create("fat") {
         }
     }
    dependencies {
        compile fileTree(include: ['*.jar'], dir: 'libs')
        compile 'com.android.support:appcompat-v7:23.0.0'
        compile project(':openCVLibrary2411')
    }

通过此更改，我可以在 jni 文件夹下的 c++ 文件中调用我的本机虚拟函数。 #include <opencv2/core/core.hpp> 和其他人也得到 CLion 的支持...当我声明 cv::Mat mat;给我这个错误：

Linker failed while linking libmymodule.so failed.
C:\DevAndroid\OpenCV-android-sdk\sdk\native\jni\include/opencv2/core/mat.hpp:278: error: undefined reference to 'cv::fastFree(void*)'
C:\DevAndroid\OpenCV-android-sdk\sdk\native\jni\include/opencv2/core/mat.hpp:367: error: undefined reference to 'cv::Mat::deallocate()'
collect2.exe: error: ld returned 1 exit status

C++代码：

#include <jni.h>
#include <vector>
#include <string>
#include "helpers.h"
#include <opencv2/core/core.hpp> //This is supported by CLion
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace std;

extern "C" {
JNIEXPORT jstring JNICALL
Java_android_overloaded_nativetestv4_MainActivity_FuncV1(JNIEnv *env, jclass type) {
    cv::Mat mat; //causing error

    string s = "Cpp v1 - succ ";
    return env->NewStringUTF(s.data());
}

}

更新

- 添加 "z" 到 ldLibs
- 添加了 android.productFlavors 方块

现在编译成功，应用程序第二次启动然后崩溃并显示此消息
事件日志：

IllegalArgumentException: Error while starting native debug session: Unable to find process for android.overloaded.nativetestv4 on device huawei-huawei_y530_u00-64a6513ccd8e

调试信息：

Restart ADB integration and try again
Waiting for process: android.overloaded.nativetestv4
DEVICE SHELL COMMAND: run-as android.overloaded.nativetestv4 mkdir -p /data/data/android.overloaded.nativetestv4/lldb/bin
DEVICE SHELL COMMAND: cat /data/local/tmp/lldb-server | run-as android.overloaded.nativetestv4 sh -c 'cat > /data/data/android.overloaded.nativetestv4/lldb/bin/lldb-server; chmod 700 /data/data/android.overloaded.nativetestv4/lldb/bin/lldb-server'
DEVICE SHELL COMMAND: rm /data/local/tmp/lldb-server
DEVICE SHELL COMMAND: cat /data/local/tmp/start_lldb_server.sh | run-as android.overloaded.nativetestv4 sh -c 'cat > /data/data/android.overloaded.nativetestv4/lldb/bin/start_lldb_server.sh; chmod 700 /data/data/android.overloaded.nativetestv4/lldb/bin/start_lldb_server.sh'
DEVICE SHELL COMMAND: rm /data/local/tmp/start_lldb_server.sh
Now Launching Native Debug Session
Error while starting native debug session: java.lang.IllegalArgumentException: Unable to find process for android.overloaded.nativetestv4 on device huawei-huawei_y530_u00-64a6513ccd8e

日志：

A/libc﹕ Fatal signal 11 (SIGSEGV) at 0x00000000 (code=1), thread 3077 (ed.nativetestv4)

Answer 1

经过几周的痛苦，我成功了。这是 Android studio 1.3.1、OpenCv 2.4.11 的正确代码。首先你应该这样做 OpenCV in Android Studio （不要使用包含白色 space 的路径用于项目和 opencv 提取文件夹）然后，对于 opencv 是本机的：

gradle-wrapper.properties:

distributionUrl=https\://services.gradle.org/distributions/gradle-2.5-all.zip

build.gradle(申请):

classpath 'com.android.tools.build:gradle-experimental:0.2.0'

build.gradle(模块):

apply plugin: 'com.android.model.application'

model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.0"

        defaultConfig.with {
            applicationId = "android.overloaded.nativetestv4"
            minSdkVersion.apiLevel = 18
            targetSdkVersion.apiLevel = 23
            versionCode = 1
            versionName = "1.0"
        }
    }


    android.ndk{
        moduleName = "mymodule"
        ldLibs += ['log']
        cppFlags += "-std=c++11"
        cppFlags += "-fexceptions"
        cppFlags  += "-I${file("C:/DevAndroid/OpenCV-android-sdk/sdk/native/jni/include")}".toString()
        cppFlags  += "-I${file("C:/DevAndroid/OpenCV-android-sdk/sdk/native/jni/include/opencv")}".toString()



//        ldFlags += linkOpt
        ldLibs += ["android", "EGL", "GLESv2", "dl", "log", "z"]// , "ibopencv_core"
        stl = "gnustl_shared"//"gnustl_static"//"gnustl_shared"//"stlport_static"
    }

    android.buildTypes {
        release {
            minifyEnabled = false
            proguardFiles += file('proguard-rules.pro')
        }
    }

    android.productFlavors {
        create("arm") {
            ndk.with {
                abiFilters += "armeabi"

                File curDir = file('./')
                curDir = file(curDir.absolutePath)
                String libsDir = curDir.absolutePath+"\src\main\jniLibs\armeabi\" //"-L" +

                ldLibs += libsDir + "libnative_camera_r4.3.0.so"
                ldLibs += libsDir + "libopencv_contrib.a"
                ldLibs += libsDir + "libopencv_core.a"
                ldLibs += libsDir + "libopencv_highgui.a"
                ldLibs += libsDir + "libopencv_imgproc.a"
                ldLibs += libsDir + "libopencv_info.so"
                ldLibs += libsDir + "libopencv_java.so"
                ldLibs += libsDir + "libopencv_legacy.a"
                ldLibs += libsDir + "libopencv_ml.a"
                ldLibs += libsDir + "libopencv_ts.a"

            }
        }
        create("armv7") {
            ndk.with {
                abiFilters += "armeabi-v7a"

                File curDir = file('./')
                curDir = file(curDir.absolutePath)
                String libsDir = curDir.absolutePath+"\src\main\jniLibs\armeabi-v7a\" //"-L" +

                ldLibs += libsDir + "libnative_camera_r4.3.0.so"
                ldLibs += libsDir + "libopencv_contrib.a"
                ldLibs += libsDir + "libopencv_core.a"
                ldLibs += libsDir + "libopencv_highgui.a"
                ldLibs += libsDir + "libopencv_imgproc.a"
                ldLibs += libsDir + "libopencv_info.so"
                ldLibs += libsDir + "libopencv_java.so"
                ldLibs += libsDir + "libopencv_legacy.a"
                ldLibs += libsDir + "libopencv_ml.a"
                ldLibs += libsDir + "libopencv_ts.a"

            }
        }
        create("x86") {
            ndk.with {
                abiFilters += "x86"
            }
        }
        create("mips") {
            ndk.with {
                abiFilters += "mips"
            }
        }
        create("fat") {

        }
    }

}
dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:23.0.0'
    compile project(':openCVLibrary2411')
}

.cpp

#include <jni.h>
#include <vector>
#include <string>
#include "helpers.h"
#include <opencv2/core/core.hpp>

using namespace std;

#ifdef __cplusplus
extern "C" {
#endif



JNIEXPORT jstring JNICALL
Java_android_overloaded_nativetestv4_MainActivity_FuncV1(JNIEnv *env, jclass type) {

    cv::Mat mat(33,22, 1);

    string s = "Cpp v1 - succ, rows#:" + Helpers::ToStringNum(mat.rows);
    Helpers::Log(s);

    return env->NewStringUTF(s.data());
}

}

.java

package android.overloaded.nativetestv4;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity
{
    static {
        System.loadLibrary("mymodule");
    }

    public static native String FuncV1();

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toast.makeText(this, FuncV1(), Toast.LENGTH_LONG).show();

        ((TextView)findViewById(R.id.txtInfo)).setText(FuncV1());
    }

更新 Android Studio 1.5.1、OpenCV 3.1
1.首先你应该这样做OpenCV in Android Studio（不要使用包含白色的路径space，对于项目和opencv提取文件夹），之后你应该有正常工作Java应用程序
2.更改项目根目录中的build.gradle：

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath "com.android.tools.build:gradle-experimental:0.4.0"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

改变gradle-wrapper.properties：

distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-2.8-all.zip

在opencv模块中更改build.gradle：

apply plugin: 'com.android.model.library'

model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.2"
        defaultConfig.with {
            minSdkVersion.apiLevel = 11
            targetSdkVersion.apiLevel = 23
        }


    }

    android.buildTypes {
        release {
            minifyEnabled = false
            proguardFiles.add(file("proguard-rules.txt"))
        }
    }
}

在应用程序模块中更改build.gradle：

apply plugin: 'com.android.model.application'

model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.2"

        defaultConfig.with {
            applicationId = "android.overloaded.opencv31v1" //Name of package
            minSdkVersion.apiLevel = 11
            targetSdkVersion.apiLevel = 23
            versionCode = 1
            versionName = "1.0"

        }
    }

    android.ndk {
        moduleName = "native" // Name of C++ module, for System.loadLibrary("native")
        cppFlags.add("-std=c++11") // Add provisions to allow C++11 functionality
        cppFlags.add("-fexceptions")
        // YOUR OPENCV DIRECTORY!!!
        cppFlags.add("-I${file("C:/DevAndroid/OpenCV-android-sdk/sdk/native/jni/include")}".toString()) 
        ldLibs.addAll(["android", "EGL", "GLESv2", "dl", "log", "z"])
        stl = "gnustl_shared"
    }

    android.buildTypes {
        release {
            minifyEnabled = false
            proguardFiles.add(file("proguard-rules.txt"))
        }
    }

    android.productFlavors {
        create("arm") {
            ndk.with{
                abiFilters.add("armeabi")

                File curDir = file('./')
                curDir = file(curDir.absolutePath)
                String libsDir = curDir.absolutePath + "\src\main\jniLibs\armeabi\"

                ldLibs.add(libsDir + "libopencv_core.a")
                ldLibs.add(libsDir + "libopencv_highgui.a")
                ldLibs.add(libsDir + "libopencv_imgproc.a")
                ldLibs.add(libsDir + "libopencv_java3.so")
                ldLibs.add(libsDir + "libopencv_ml.a")

            }
        }
        create("armv7") {
            ndk.with {
                abiFilters.add("armeabi-v7a")

                File curDir = file('./')
                curDir = file(curDir.absolutePath)
                String libsDir = curDir.absolutePath + "\src\main\jniLibs\armeabi-v7a\"
                ldLibs.add(libsDir + "libopencv_core.a")
                ldLibs.add(libsDir + "libopencv_highgui.a")
                ldLibs.add(libsDir + "libopencv_imgproc.a")
                ldLibs.add(libsDir + "libopencv_java3.so")
                ldLibs.add(libsDir + "libopencv_ml.a")
                ldLibs.add(libsDir + "libopencv_ts.a")

            }
        }
    }
    android.sources{
        main{
            jni{
                source{
                    srcDirs += ['src/main/jniMy']
                }
            }
        }
    }
}
dependencies {
    compile fileTree(dir: "libs", include: [$/*.jar/$])
    compile "com.android.support:appcompat-v7:23.1.1" //Do not use 23.2.0 
    compile project(":openCVLibrary310")
}

创建目录 app/src/main/jniMy，这是存放您的 .cpp 文件的地方

可选择在 jniMy 中创建文件 chelper.c，代码如下：

#ifndef OPENCV31V1_CHELPER_H
#define OPENCV31V1_CHELPER_H

#include <jni.h>
#include <vector>
#include <string>
#include <sstream>
#include <android/log.h>

using namespace std;

class Helpers{
public:
    template <typename T>
    static string ToStringNum(T tNumber){
        ostringstream ostrStream;
        ostrStream << tNumber;
        return ostrStream.str();
    }

    static void Log(string s){
        __android_log_print(ANDROID_LOG_INFO, "My", s.data());
    }
    static void Log(std::exception ee){
        string s = "Exception: " + string(ee.what()) ;
        __android_log_print(ANDROID_LOG_INFO, "My", s.data());
    }

    static long Time(){
        struct timespec now;
        clock_gettime(CLOCK_MONOTONIC, &now);
        return (long)((int64_t)now.tv_sec * 1000LL + now.tv_nsec /1000000LL);
    }
    static string Time(long iTime){
        return ToStringNum(Time() - iTime) + "ms";
    }

};
#endif //OPENCV31V1_CHELPER_H

在 jniMy 中创建文件 native_exporter.cpp，代码如下：

#include <jni.h>
#include <string>
#include <opencv2/core/core.hpp>
#include "chelper.h"

extern "C"{
JNIEXPORT jstring     JNICALLJava_android_overloaded_opencv31v1_MainActivity_FuncV1(JNIEnv *env,
jclass type) {

    cv::Mat mat(33,22, CV_32FC2);

    string s = "Cpp v1 - succ, rows#:" +Helpers::ToStringNum(mat.rows);
    Helpers::Log(s);
    auto i = 5;
    for (int i2 : {1,3,5}){
        Helpers::Log(Helpers::ToStringNum(i2));
    }

    return env->NewStringUTF(s.data());
}
}

MainActivity.java中的代码：

package android.overloaded.opencv31v1;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.SurfaceView;
import android.widget.TextView;
import android.widget.Toast;

import org.opencv.android.CameraBridgeViewBase;
import org.opencv.core.CvType;
import org.opencv.core.Mat;

public class MainActivity extends AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener2
{
    private static void Log(String sMsg){Log.i("My", "MainActivity." + sMsg );}

    static{
        System.loadLibrary("opencv_java3");
        System.loadLibrary("native");
    }

    public native String FuncV1();
    JavaCameraViewCustom2 _javaCameraView; //Similar to JavaCameraView

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if(getSupportActionBar() != null)getSupportActionBar().hide();
        String sRes = FuncV1();
        Toast.makeText(this, sRes, Toast.LENGTH_LONG).show();

        ((TextView)findViewById(R.id.txtInfo)).setText(sRes);

        _javaCameraView = (JavaCameraViewCustom2)findViewById(R.id.cameraView);
        _javaCameraView.setVisibility(SurfaceView.VISIBLE);
        _javaCameraView.setCvCameraViewListener(this);

    }

    @Override
    protected void onResume()
    {
        super.onResume();
        _javaCameraView.enableView();
    }

    @Override
    protected void onPause()
    {
        super.onPause();
        _javaCameraView.disableView();
    }

    Mat _imgBgrTemp;
    @Override
    public void onCameraViewStarted(int width, int height)
    {
        _imgBgrTemp = new Mat(height,width, CvType.CV_8UC4);
    }

    @Override
    public void onCameraViewStopped()
    {
        _imgBgrTemp.release();
    }

    @Override
    public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame)
    {
        _imgBgrTemp = inputFrame.rgba();
        return _imgBgrTemp;
    }
}

Android Studio 会要求您更改 jdk，它还会安装新的 gradle，您应该按照它的要求进行所有操作。

OpenCv with Android studio 1.3+ 使用新的 gradle - undefined reference

OpenCv with Android studio 1.3+ using new gradle - undefined reference

opencv

android-ndk

android-studio

android-gradle-plugin

opencv4android