更改方向会导致相机破坏其当前活动，然后重新创建它

Question

我正在使用自定义相机来捕捉图片，并且支持所有设备和屏幕方向我写了两个不同的 - 不同的xmls 。

一个 人像模式（在 res＆gt;布局下）和第二个 横向模式（在 res＆gt; layout-land 下）

举个例子：

1. 我的相机已经初始化，我已准备好拍摄/拍摄图像 ----＆gt;＆gt;＆gt;我的 相机预览模式仍为横向

2. 现在我决定使用人像模式（所以我改变了相机的旋转度）从 LANDSCAPE模式到PORTRAIT模式 ，但在以人像模式启动相机之前，关闭并打开相机镜头......（简而言之，重新初始化我的相机）

CameraLauncherActivity.java： -

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_camera);

         mCamera = getCameraInstance();

            mCameraPreview = new PreviewSurface(this, mCamera);
            FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
            preview.addView(mCameraPreview);

            Button captureButton = (Button) findViewById(R.id.btnCapture);
            Log.d(CameraLauncherActivity.LOG_TAG, "captureButton :: " + captureButton);
            captureButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mCamera.takePicture(null, null, mPicture);
                    Log.d(CameraLauncherActivity.LOG_TAG, "mCamera.takePicture :: " + mCamera);                                         
                }
            });
                  }
          private Camera getCameraInstance() {

        Camera camera = null;
        Log.d(CameraLauncherActivity.LOG_TAG, "getCameraInstance()Camera:: " + camera);
        try {
            camera = Camera.open(0);
            Log.d(CameraLauncherActivity.LOG_TAG, "getCameraInstance()open:: " + camera);
        } catch (Exception e) {
            // cannot get camera or does not exist
        }
        if(camera!=null){
         // get supported sizes:
         // List<Size> localSizes = camera.getParameters().getSupportedPreviewSizes();
         // loop through localSizes to get closest size
         Camera.Parameters parameters = camera.getParameters();
         parameters.setPreviewSize(640, 480);
         camera.setParameters(parameters);
        }
        return camera;
    }

    PictureCallback mPicture = new PictureCallback() {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            pictureFile = getOutputMediaFile();
            camera.startPreview();
            if (pictureFile == null) {
                return;
            }
            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.close();
            } catch (FileNotFoundException e) {

            } catch (IOException e) {
            }
        }
    };

PreviewSurface.java： -

 public class PreviewSurface extends SurfaceView implements
SurfaceHolder.Callback {

    public static final String LOG_TAG = "CameraPreview";
    private SurfaceHolder mSurfaceHolder;

    private Camera mCamera;

    // Constructor that obtains context and camera
    @SuppressWarnings("deprecation")
    public PreviewSurface(Context context, Camera camera) {
        super(context);
        this.mCamera = camera;

        this.mSurfaceHolder = this.getHolder();
        this.mSurfaceHolder.addCallback(this);
        this.mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        this.mSurfaceHolder.setFixedSize(100, 100);
    }

    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
        try {       
            Camera.Parameters parameters = mCamera.getParameters();
            if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) 
            {
                 parameters.set("orientation", "portrait");
                 mCamera.setDisplayOrientation(90);
                 parameters.setRotation(90);
                 mCamera.setPreviewDisplay(surfaceHolder);
                 mCamera.startPreview();
            }
            else 
            {
                 // This is an undocumented although widely known feature
                 parameters.set("orientation", "landscape");
                 // For Android 2.2 and above
                 mCamera.setDisplayOrientation(0);
                 // Uncomment for Android 2.0 and above
                 parameters.setRotation(0);
            }
            mCamera.setPreviewDisplay(surfaceHolder);
            mCamera.startPreview();

        } catch (IOException e) {
            // left blank for now
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
        mCamera.stopPreview();
        mCamera.release();
    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int format,
            int width, int height) {

        try {       
            Camera.Parameters parameters = mCamera.getParameters();
            if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
                 parameters.set("orientation", "portrait");
                 mCamera.setDisplayOrientation(90);
                 parameters.setRotation(90);

            }
                 else {
                      // This is an undocumented although widely known feature
                      parameters.set("orientation", "landscape");
                      // For Android 2.2 and above
                      mCamera.setDisplayOrientation(0);
                      // Uncomment for Android 2.0 and above
                      parameters.setRotation(0);
            }
            mCamera.setPreviewDisplay(surfaceHolder);
            mCamera.startPreview();

        } catch (IOException e) {
            // left blank for now
        }           
    }

的Manifest.xml： -

    <activity
        android:name="com.example.camera.CameraLauncherActivity"
        android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen" />

Answer 1

是的，这就是它的工作方式，关闭活动，破坏表面。但如果您认为camera.open（）太慢而无法经常调用，则可以将camera.release()延迟到Activity.onStop（）。