我在 APK 中有以下类代码，进行面部检测并在相机预览上绘制自定义视图。面部检测在我的“Samsung-S3”上运行良好，但我在其他几部从未启动面部检测的安卓手机上对其进行了测试。为什么会这样/如何让它工作？（请不要介意缩进）
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
private MyDrawing md;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void refreshCamera(Camera camera) {
if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
setCamera(camera);
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
//startFaceDetection();
} catch (Exception e) {
Log.d(VIEW_LOG_TAG, "Error starting camera preview: " + e.getMessage());
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
refreshCamera(mCamera);
}
public void setCamera(Camera camera) {
//method to set a camera instance
mCamera = camera;
mCamera.setFaceDetectionListener(faceDetectionListener);
startFaceDetection();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
mCamera.release();
}
private Camera.FaceDetectionListener faceDetectionListener = new Camera.FaceDetectionListener() {
@Override
public void onFaceDetection(Camera.Face[] faces, Camera c) {
if (faces.length > 0) {
Log.d("FaceDetection", "face detected X and Y are as: " + faces.length +
" Face 1 Location X: " + faces[0].rect.centerX() +
"Y: " + faces[0].rect.centerY() +" LIES IN "+(MyDrawing.w-MyDrawing.radius) +"--"+(MyDrawing.w+MyDrawing.radius));
if(faces[0].rect.centerX()>=0 && faces[0].rect.centerX()<115 )
{
Log.d("ALERT = ", "Detection Started" );
AndroidVideoCaptureExample.capture.setText("Recording/ stopNsave ");
AndroidVideoCaptureExample.faceDetect();
}
} else {
Log.d("FaceDetection", "circle cordinates are as: " + (MyDrawing.w-MyDrawing.radius) +"cX"+ MyDrawing.radius+"cY");
}
}
};
public void startFaceDetection(){
// Try starting Face Detection
Camera.Parameters params = mCamera.getParameters();
// start face detection only *after* preview has started
if (params.getMaxNumDetectedFaces() > 0){
// camera supports face detection, so can start it:
mCamera.startFaceDetection();
}
}
最小支持的 SDK 设置为 10