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我正在为 API 7 (2.1) 开发。我实现了这样的相机视图：

public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
SurfaceHolder mHolder;

int width;
int height;

Camera mCamera;

public CameraView(Context context, AttributeSet attrs) {
    super(context, attrs);
    initHolder();
}

public CameraView(Context context) {
    super(context);
    initHolder();
}

private void initHolder() {
    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, acquire the camera and tell it where to
    // draw.
    mCamera = Camera.open();

//      Parameters params = mCamera.getParameters();
//      // If we aren't landscape (the default), tell the camera we want
//      // portrait mode
//      if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
//          params.set("orientation", "portrait"); // "landscape"
//          // And Rotate the final picture if possible
//          // This works on 2.0 and higher only
//          // params.setRotation(90);
//          // Use reflection to see if it exists and to call it so you can
//          // support older versions
//          try {
//              Method rotateSet = Camera.Parameters.class.getMethod("setRotation", new Class[] { Integer.TYPE });
//              Object arguments[] = new Object[] { new Integer(90) };
//              rotateSet.invoke(params, arguments);
//          } catch (NoSuchMethodException nsme) {
//              // Older Device
//              Log.v("CAMERAVIEW", "No Set Rotation");
//          } catch (IllegalArgumentException e) {
//              Log.v("CAMERAVIEW", "Exception IllegalArgument");
//          } catch (IllegalAccessException e) {
//              Log.v("CAMERAVIEW", "Illegal Access Exception");
//          } catch (InvocationTargetException e) {
//              Log.v("CAMERAVIEW", "Invocation Target Exception");
//          }
//      }
//      mCamera.setParameters(params);
    setDisplayOrientation(mCamera, 90);

    try {
        mCamera.setPreviewDisplay(holder);
    } catch (IOException exception) {
        mCamera.release();
        mCamera = null;
    }
}

public void surfaceDestroyed(SurfaceHolder holder) {
    // Surface will be destroyed when we return, so stop the preview.
    // Because the CameraDevice object is not a shared resource, it's very
    // important to release it when the activity is paused.
    mCamera.stopPreview();
    mCamera.release();
    mCamera = null;
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    width = w;
    height = h;
    // Now that the size is known, set up the camera parameters and begin the preview.
    Camera.Parameters parameters = mCamera.getParameters();
    //parameters.setPreviewSize(w, h);
    mCamera.setParameters(parameters);

    mCamera.startPreview();
}

public void takePicture(Camera.ShutterCallback shutter, Camera.PictureCallback raw, Camera.PictureCallback jpeg) {
    mCamera.takePicture(shutter, raw, jpeg);
}

protected void setDisplayOrientation(Camera camera, int angle){
    Method downPolymorphic;
    try {
        downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class });
        if (downPolymorphic != null) {
            downPolymorphic.invoke(camera, new Object[] { angle });
        }

    } catch (Exception e1) {}
}
}

只有使用反射的方法（取自 Williew 在Android camera rotate中的回答）才能在我的设备上显示正确旋转的预览，否则，预览总是旋转 -90°

到目前为止一切顺利，但现在我遇到了另一个问题。当我得到带有活动回调的位图时：

public void onPictureTaken(byte[] data, Camera camera) {
    Bitmap b = BitmapFactory.decodeByteArray(data, 0, data.length);

    Log.d("test", "---width: "  + b.getWidth() + " height: " + b.getHeight());
}

它始终处于横向模式！（在本例中为 2560 x 1920）。因此，如果用户在纵向模式下手持设备拍摄照片，我会得到一张 2560 x 1920 的位图，无论如何，当我放入图像视图时，由于某种原因，它看起来与我拍摄的纵向照片一模一样。当用户在横向模式下拿着设备的照片时出现问题，我想旋转它，以便以纵向模式（按比例缩小）显示结果 - 或者对横向图片执行一些其他特殊操作。

但我无法将它们与肖像照片区分开来，因为位图的尺寸是相同的：/

如何识别纵向/横向图片？

任何想法...？我是相机新手，有点迷路了……提前谢谢。

编辑 好吧，我认为没有问题，尺寸总是相同的，因为无论我如何拿着设备，图片实际上总是相同的尺寸。唯一我不明白的是为什么当预览和图片明显处于纵向模式时我总是得到宽度>高度。

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0 回答 0