Question

我是第一次尝试设置自定义SurfaceView（除外）。

onResume / onPause被调用后我得到了“媒体服务器死机”消息。

媒体服务器死后我可以添加另一个预览。知道它崩溃的原因吗？我在onPause中释放相机并在onResume上打开相机。

- 相机活动 - 公共类CameraActivity扩展了DashboardActivity {

private static String TAG = "CameraActivity";

Camera camera;
CameraPreview cameraPreview;
Context _context;
FrameLayout frameLayout;
CameraPreview preview;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.camera_layout);

    this._context = this;
    frameLayout = (FrameLayout) findViewById(R.id.preview);

}

@Override
protected void onResume() {
    super.onResume();
    camera = Camera.open();

    if (null != camera) {
        camera.setDisplayOrientation(90);
        preview = new CameraPreview(getApplicationContext(), camera);
        frameLayout.addView(preview);
    }

}

@Override
public void onBackPressed() {
    super.onBackPressed();
    if (camera != null) {
        Log.e(TAG, "Camera was not null on back pressed!");
        try {
            camera.stopPreview();
        } catch (Exception e) {
        }
        // camera.release();
        // camera = null;
    }
    finish();
}

@Override
protected void onPause() {
    super.onPause();
    if (camera != null) {
        camera.release();
        camera = null;
    }
    frameLayout.removeView(preview);
    preview = null;
}

- 相机预览 -

public class CameraPreview extends SurfaceView implements
    SurfaceHolder.Callback {
private static final String TAG = "Preview";

SurfaceHolder mHolder;
public Camera camera;

CameraPreview(Context context, Camera camera) {
    super(context);

    this.camera = camera;
    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);
    mHolder.setFormat(PixelFormat.RGB_332);
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_GPU);
}

public void surfaceCreated(SurfaceHolder holder) {
    try {
        Camera.Parameters p = camera.getParameters();
        p.setPictureSize(80, 60);
        p.setColorEffect(android.hardware.Camera.Parameters.EFFECT_NONE);
        p.setJpegQuality(20);
        p.setPreviewFrameRate(1);
        p.setPreviewFpsRange(5, 10);
        p.setPreviewSize(80, 60);
        camera.setParameters(p);
        try {
            camera.setPreviewDisplay(holder);

            camera.setPreviewCallback(new PreviewCallback() {

                public void onPreviewFrame(byte[] data, Camera arg1) {
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void stopCameraPreview() {

}

public void takePicture() {
    camera.takePicture(null, null, null);
    stopCameraPreview();

}

public void surfaceDestroyed(SurfaceHolder holder) {
    Log.e(TAG, "SurfaceDestroyed called");
    if (camera != null) {
        try {
            camera.stopPreview();
        } catch (Exception e) {
        }
        // camera.lock();
        // camera.release();
        // camera = null;
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {

    Log.d(TAG, "SurfaceChanged called!");

    if (holder.getSurface() == null) {
        Log.d(TAG, "SurfaceChanged Surface is null! Stopping!");
        return;
    }

    try {
        Camera.Parameters parameters = camera.getParameters();
        // parameters.setPreviewSize(80, 60);
        camera.setParameters(parameters);
        // camera.setPreviewDisplay(holder);

        camera.startPreview();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

}

Answer 1

停止相机的正确方法是

   public void onPause() {
    super.onPause();
    releaseCamera();
}

和

public void releaseCamera() {
    if (mCamera != null) {
        mCamera.stopPreview();
        mCamera.setPreviewCallback(null);
        mCamera.release();
        mCamera = null;
    }
}

onPause / onBackPressed后Android Surface Camera Preview崩溃

1 个答案: