三星银河王牌Surfaceview /相机错误

Question

I am writting an app that is supposed to be compatible with the samsung galaxy ace. I have the following code:

mPreview = (SurfaceView)findViewById(R.id.preview);
mPreview.getHolder().addCallback(this);
mPreview.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mCamera.setDisplayOrientation(0);           
mCamera = Camera.open();

It crashes at

mCamera.setDisplayOrientation(0);

And gives the following error:

/AndroidRuntime(18011): Caused by: java.lang.NullPointerException

I have tried to set the value to 90, 180, 270 and 360, but nothing seems to solve this issue.

Answer 1

It is because mCamera is null.

You should call setDisplayOrientation() after Camera.open() .

It is written in Android developer site ( http://developer.android.com/reference/android/hardware/Camera.html ).