相机预览在Android中不全屏

Question

I am trying to take the camera preview and alter it in onPreviewFrame() and show it to the user. I have already achieved the required functionality but the problem is in SIZE OF CAMERA PREVIEW.It always takes smaller part of the screen and i want to make it fullscreen ie want to take the camera preview which should fill whole screen of the device.I have read and tried any solutions available on net but none of them is working in my case.This is the Surface View class:

public class MySurfaceView extends SurfaceView implements Callback, Camera.PreviewCallback, android.view.SurfaceHolder.Callback {

    private static final String TAG = "MySurfaceView";
    private int width;
    private int height;
    public SurfaceHolder mHolder;
    private Camera mCamera;
    private int[] rgbints;
    private int mMultiplyColor;

    public MySurfaceView(Context context, AttributeSet attrs , Camera camera , 
            int width , int height) 
    {
        super(context, attrs);

        mCamera = camera;

        this.width = width;
        this.height = height;

        mHolder = getHolder();
        mHolder.addCallback(this);

        mMultiplyColor = getResources().getColor(R.color.honeydew);
    }


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


    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        synchronized (this) {
            this.setWillNotDraw(false); // This allows us to make our own draw calls to this canvas

            rgbints = new int[width * height];

            // try { mCamera.setPreviewDisplay(holder); } catch (IOException e)
            // { Log.e("Camera", "mCamera.setPreviewDisplay(holder);"); }

            mCamera.startPreview();
            mCamera.setPreviewCallback(this);

        }
    }


    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        synchronized (this) {
            try
            {
                CameraActivity cameraActivity = new CameraActivity();
                cameraActivity.releaseCamera();
                cameraActivity = null;
            } catch (Exception e) {
                Log.e("Camera", e.getMessage());
            }
        }
    }

    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        Canvas canvas = null;

        if (mHolder == null) 
        {
            return;
        }

        try {
            synchronized (mHolder) 
            {
                canvas = mHolder.lockCanvas(null);

                int canvasWidth = canvas.getWidth();
                int canvasHeight = canvas.getHeight();

                decodeYUV(rgbints, data, width, height);

                // draw the decoded image, centered on canvas
                canvas.drawBitmap(rgbints, 0, width, canvasWidth-((width+canvasWidth)>>1), canvasHeight-((height+canvasHeight)>>1), width, height, false, null);

                // use some color filter
                canvas.drawColor(mMultiplyColor, Mode.MULTIPLY);

            }
        }  catch (Exception e){
            e.printStackTrace();
        } finally {
            // do this in a finally so that if an exception is thrown
            // during the above, we don't leave the Surface in an
            // inconsistent state
            if (canvas != null)
            {
                mHolder.unlockCanvasAndPost(canvas);
                canvas = null;
            }
        }
    }


    public void decodeYUV(int[] out, byte[] fg, int width, int height) throws NullPointerException, IllegalArgumentException {
        int sz = width * height;
        if (out == null)
            throw new NullPointerException("buffer out is null");
        if (out.length < sz)
            throw new IllegalArgumentException("buffer out size " + out.length + " < minimum " + sz);
        if (fg == null)
            throw new NullPointerException("buffer 'fg' is null");
        if (fg.length < sz)
            throw new IllegalArgumentException("buffer fg size " + fg.length + " < minimum " + sz * 3 / 2);
        int i, j;
        int Y, Cr = 0, Cb = 0;
        for (j = 0; j < height; j++) {
            int pixPtr = j * width;
            final int jDiv2 = j >> 1;
        for (i = 0; i < width; i++) {
            Y = fg[pixPtr];
            if (Y < 0)
                Y += 255;
            if ((i & 0x1) != 1) {
                final int cOff = sz + jDiv2 * width + (i >> 1) * 2;
                Cb = fg[cOff];
                if (Cb < 0)
                    Cb += 127;
                else
                    Cb -= 128;
                Cr = fg[cOff + 1];
                if (Cr < 0)
                    Cr += 127;
                else
                    Cr -= 128;
            }
            int R = Y + Cr + (Cr >> 2) + (Cr >> 3) + (Cr >> 5);
            if (R < 0)
                R = 0;
            else if (R > 255)
                R = 255;
            int G = Y - (Cb >> 2) + (Cb >> 4) + (Cb >> 5) - (Cr >> 1) + (Cr >> 3) + (Cr >> 4) + (Cr >> 5);
            if (G < 0)
                G = 0;
            else if (G > 255)
                G = 255;
            int B = Y + Cb + (Cb >> 1) + (Cb >> 2) + (Cb >> 6);
            if (B < 0)
                B = 0;
            else if (B > 255)
                B = 255;
            out[pixPtr++] = 0xff000000 + (B << 16) + (G << 8) + R;
        }
        }

    }

    public void showSupportedCameraFormats(Parameters p) {
        List<Integer> supportedPictureFormats = p.getSupportedPreviewFormats();
        Log.d(TAG, "preview format:" + cameraFormatIntToString(p.getPreviewFormat()));
        for (Integer x : supportedPictureFormats) {
            Log.d(TAG, "suppoterd format: " + cameraFormatIntToString(x.intValue()));
        }

    }

    @SuppressWarnings("deprecation")
    private String cameraFormatIntToString(int format) {
        switch (format) {
        case PixelFormat.JPEG:
            return "JPEG";
        case PixelFormat.YCbCr_420_SP:
            return "NV21";
        case PixelFormat.YCbCr_422_I:
            return "YUY2";
        case PixelFormat.YCbCr_422_SP:
            return "NV16";
        case PixelFormat.RGB_565:
            return "RGB_565";
        default:
            return "Unknown:" + format;

        }
    }
}

This is the caller class:

public class CameraActivity extends Activity {

    private Camera mCamera;
    private MySurfaceView surfaceView;
    private RelativeLayout relativeLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.activity_main);
    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        releaseCamera();
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();

        releaseCamera();
    }

    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();

        mCamera = Camera.open();

        Camera.Parameters p = mCamera.getParameters();
        Size size = p.getPreviewSize();
        int width = size.width;
        int height = size.height;
        p.setPreviewFormat(ImageFormat.JPEG);
        mCamera.setParameters(p);


        surfaceView = new MySurfaceView(this, null , mCamera ,width , height);

        RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);

        surfaceView.setLayoutParams(layoutParams);

        relativeLayout = (RelativeLayout)findViewById(R.id.relativeLayout);

        relativeLayout.addView(surfaceView);

        surfaceView.showSupportedCameraFormats(p);
    }

    public void releaseCamera()
    {
        if (mCamera != null)
        {
            mCamera.stopPreview();
            mCamera.setPreviewCallback(null);
            surfaceView.getHolder().removeCallback(surfaceView);
            mCamera.release();        // release the camera for other applications
            mCamera = null;

            surfaceView.mHolder.removeCallback(surfaceView);
            surfaceView.mHolder = null;

            surfaceView = null;

            relativeLayout.removeAllViews();
            relativeLayout.removeAllViewsInLayout();
            relativeLayout = null;
        }

    }
}

Please help me.Thanks in advance.

EDIT:

Xml is :

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:id="@+id/relativeLayout"    
    android:layout_height="match_parent" >

</RelativeLayout>

Answer 1

instend of relativelayout take linearlayout and put framelayout in it:

<FrameLayout
            android:id="@+id/preview"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_weight="1" >
        </FrameLayout>

and then set camerapreview in it:

surfaceView = new MySurfaceView(this, null , mCamera ,width , height);

((FrameLayout) findViewById(R.id.preview)).addView(surfaceView);

CameraPreview.java

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

    SurfaceHolder mHolder;
    public Camera camera;

    CameraPreview(Context context) {
        super(context);

        // 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.

        if(camera == null){
        camera = Camera.open();


        camera.setDisplayOrientation(90);
        try {
            camera.setPreviewDisplay(holder);


            camera.setPreviewCallback(new PreviewCallback() {

                public void onPreviewFrame(byte[] data, Camera arg1) {

                        CameraPreview.this.invalidate();
                }
            });
        } catch (IOException e) {
           camera.release();
           camera = 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.
        if(camera!=null){
            camera.stopPreview();
            camera.setPreviewCallback(null);

            camera.release();
            camera = null;
        }

    }

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

    @Override
    public void draw(Canvas canvas) {
            super.draw(canvas);
            Paint p= new Paint(Color.RED);
            Log.d(TAG,"draw");
            canvas.drawText("PREVIEW", canvas.getWidth()/2, canvas.getHeight()/2, p );
    }

    public void releaseCameraAndPreview() {
         if (camera != null) {
            camera.release();
            camera = null;
        }
    }
}