让Camera在portrait模式下不旋转90度

由于Android自身的关系，camera必须在landscape模式下才可以显示正常，如果是在portrait模式下，就要把脖子转90度才能“正常”观看了

听说Android的SDK升级到1.5(cupcake)后已经可以解决这个问题了，就上网找了一下，发现有些人说可以尝试使用parameters.set("rotation", 90)，试了一下，无效。

最近由于项目原因，继续研究了下，找到了一个“曲线救国”的方法
parameters.set("orientation", "portrait");

由于这个方法没有出现在Android的官方的api文档中，所以可能会有些问题。。。吧
谁知道呢，先用着再说

（哎，这个方法被2.0毙了）

-----------------------更新-----------------------

通过反射，貌似可以解决预览
1.5 - OK
1.6 - OK
2.2 - OK
2.3 - OK
4.0 - OK
其余的没有测试，希望有能力的朋友帮忙测一下，然后给个结果

public class CameraView extends SurfaceView implements SurfaceHolder.Callback {

	/**
	 * This is a holder that holding a display surface.
	 */
	private SurfaceHolder mHolder = null;

	private int sdk = 3;

	/**
	 * This is a camera object using for connect/disconnect with the camera
	 * service,and so on.
	 */
	private Camera mCamera;

	/**
	 * Perform inflation from XML and apply a class-specific base style. This
	 * constructor of View allows subclasses to use their own base style when
	 * they are inflating.
	 * 
	 * @param context
	 *            The Context the view is running in, through which it can
	 *            access the current theme, resources, etc.
	 * @param attrs
	 *            The attributes of the XML tag that is inflating the view.
	 * @param defStyle
	 *            The default style to apply to this view. If 0, no style will
	 *            be applied (beyond what is included in the theme). This may
	 *            either be an attribute resource, whose value will be retrieved
	 *            from the current theme, or an explicit style resource.
	 */
	public CameraView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		init();
	}

	/**
	 * Constructor that is called when inflating a view from XML. This is called
	 * when a view is being constructed from an XML file, supplying attributes
	 * that were specified in the XML file. This version uses a default style of
	 * 0, so the only attribute values applied are those in the Context's Theme
	 * and the given AttributeSet.
	 * 
	 * @param context
	 *            The Context the view is running in, through which it can
	 *            access the current theme, resources, etc.
	 * @param attrs
	 *            The attributes of the XML tag that is inflating the view.
	 */
	public CameraView(Context context, AttributeSet attrs) {
		super(context, attrs);
		init();
	}

	/**
	 * Simple constructor to use when creating a view from code.
	 * 
	 * @param context
	 *            The Context the view is running in, through which it can
	 *            access the current theme, resources, etc.
	 */
	public CameraView(Context context) {
		super(context);
		init();
	}

	public void init() {
		if (mHolder == null) {
			mHolder = getHolder();
			mHolder.addCallback(this);
			mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

			sdk = getSDKInt();
		}
	}

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

		try {

			// rotate camera 90 degree on portrait mode
			if (getContext().getResources().getConfiguration().orientation == ActivityInfo.SCREEN_ORIENTATION_PORTRAIT) {

				if (sdk <= 4) {

					// 1.5 & 1.6
					Camera.Parameters parameters = mCamera.getParameters();
					parameters.set("orientation", "portrait");
					mCamera.setParameters(parameters);
				} else {
					setDisplayOrientation(mCamera, 90);
				}
			}

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

		startPreview();
	}

	/**
	 * rotate camera with any degree, only available for SDK 5 and later
	 * 
	 * @param camera
	 * @param angle
	 */
	private void setDisplayOrientation(Camera camera, int angle) {
		Method downPolymorphic;

		if (sdk <= 4)
			return;

		try {
			if (sdk > 4 && sdk < 8) {

				// parameters for pictures created by a Camera service.
				Camera.Parameters parameters = mCamera.getParameters();

				// 2.0, 2.1
				downPolymorphic = parameters.getClass().getMethod(
						"setRotation", new Class[] { int.class });
				if (downPolymorphic != null)
					downPolymorphic.invoke(parameters, new Object[] { angle });

				// Sets the Parameters for pictures from this Camera
				// service.
				mCamera.setParameters(parameters);

			} else {

				downPolymorphic = camera.getClass().getMethod(
						"setDisplayOrientation", new Class[] { int.class });
				if (downPolymorphic != null)
					downPolymorphic.invoke(camera, new Object[] { angle });
			}
		} catch (Exception e) {
		}
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {

		// get Camera object.
		try {
			mCamera = Camera.open();
			mCamera.setPreviewDisplay(holder);

		} catch (RuntimeException e) {
			e.printStackTrace();
			releaseCamera();
		} catch (IOException e) {
			e.printStackTrace();
			releaseCamera();
		}
	}

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

	public void startPreview() {
		if (mCamera != null) {
			mCamera.startPreview();
		}
	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		releaseCamera();
	}

	private void releaseCamera() {
		if (mCamera != null) {
			mCamera.stopPreview();
			mCamera.release();
		}
		mCamera = null;
		System.gc();
	}

	private int getSDKInt() {
		// this is safe so that we don't need to use SDKInt which is only
		// available after 1.6
		try {
			return Integer.parseInt(Build.VERSION.SDK);
		} catch (Exception e) {
			return 3; // default to target 1.5 cupcake
		}
	}
}

评论

2 楼 dai_lm 2010-03-29  

biAji 写道

http://code.google.com/p/android/issues/detail?id=1193

thanks, I have fixed the problem.

1 楼 biAji 2010-03-21  

http://code.google.com/p/android/issues/detail?id=1193