实现Static Initialization从而不需要安装OpenCV Manager

本文主要是介绍实现Static Initialization从而不需要安装OpenCV Manager，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

实现Static Initialization就是指将OpenCV Library添加到app package中，不需要安装OpenCV Manager这个app就能运行，官方文档有介绍，但是不详细，尤其是最后那句代码到底要放在什么地方很多人都不清楚，其实并不需要像官方文档中介绍的那样配置，我想在这里介绍下如何修改FaceDetection项目的源码来做到这点。(最好是找一个包含jni代码的项目进行修改)
[1]打开jni下的Android.mk文件，修改OpenCV的那一部分，将off设置为on，并设置OpenCV_LIB_TYPE为SHARED，结果如下：

OpenCV_CAMERA_MODULES:=on
OpenCV_INSTALL_MODULES:=on
OpenCV_LIB_TYPE:=SHARED
include ${OpenCVROOT}/sdk/native/jni/OpenCV.mk

[2]打开FdActivity.java文件，在其中添加一个静态初始化块代码，它是用来加载OpenCV_java库的，由于FaceDetection中还用了另一个库detection_based_tracker(用于人脸跟踪)，所以要在else子句中加载进来：

static {Log.i(TAG, "OpenCV library load!");if (!OpenCVLoader.initDebug()) {Log.i(TAG, "OpenCV load not successfully");} else {System.loadLibrary("detection_based_tracker");// load other libraries}
}

[3]删除FdActivity.java的OnResume()方法的最后那句，不让它去访问OpenCV Manager。

@Override
public void onResume() {super.onResume();
//OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);//
}

[4]修改FdActivity.java的OnCreate()方法，从上面的private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this)代码块中拷贝try-catch块放到OnCreate的setContentView()之后，然后拷贝mOpenCVCameraView.enableView();放到mOpenCVCameraView = (CameraBridgeViewBase) findViewById(R.id.fd_activity_surface_view);之后，修改后的OnCreate()方法如下：

public void onCreate(Bundle savedInstanceState) {Log.i(TAG, "called onCreate");super.onCreate(savedInstanceState);getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);setContentView(R.layout.face_detect_surface_view);//try {// load cascade file from application resourcesInputStream is = getResources().openRawResource(R.raw.lbpcascade_frontalface);File cascadeDir = getDir("cascade", Context.MODE_PRIVATE);mCascadeFile = new File(cascadeDir, "lbpcascade_frontalface.xml");FileOutputStream os = new FileOutputStream(mCascadeFile);byte[] buffer = new byte[4096];int bytesRead;while ((bytesRead = is.read(buffer)) != -1) {os.write(buffer, 0, bytesRead);}is.close();os.close();mJavaDetector = new CascadeClassifier(mCascadeFile.getAbsolutePath());if (mJavaDetector.empty()) {Log.e(TAG, "Failed to load cascade classifier");mJavaDetector = null;} elseLog.i(TAG, "Loaded cascade classifier from " + mCascadeFile.getAbsolutePath());mNativeDetector = new DetectionBasedTracker(mCascadeFile.getAbsolutePath(), 0);cascadeDir.delete();} catch (IOException e) {e.printStackTrace();Log.e(TAG, "Failed to load cascade. Exception thrown: " + e);}mOpenCVCameraView = (CameraBridgeViewBase)findViewById(R.id.fd_activity_surface_view);mOpenCVCameraView.enableView();//mOpenCVCameraView.setCvCameraViewListener(this);
}