放大和缩小后获取图像的高度和宽度

时间:2012-09-17 04:14:40

标签: android imageview

我试图在放大和缩小后获得图像的高度和宽度。在缩放效果后,有没有办法在Android中获得高度和宽度。我尝试了很多,但得到了图像的实际高度和宽度。

public class ImageZoomView extends View implements Observer {

    /** Paint object used when drawing bitmap. */
    private final Paint mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);

    /** Rectangle used (and re-used) for cropping source image. */
    private final Rect mRectSrc = new Rect();

    /** Rectangle used (and re-used) for specifying drawing area on canvas. */
    private final Rect mRectDst = new Rect();

    /** The bitmap that we're zooming in, and drawing on the screen. */
    private Bitmap mBitmap;

    /** Pre-calculated aspect quotient. */
    private float mAspectQuotient;

    /** State of the zoom. */
    private ZoomState mState;

    // Public methods

    /**
     * Constructor
     */
    public ImageZoomView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * Set image bitmap
     * 
     * @param bitmap The bitmap to view and zoom into
     */
    public void setImage(Bitmap bitmap) {
        mBitmap = bitmap;

        calculateAspectQuotient();

        invalidate();
    }

    /**
     * Set object holding the zoom state that should be used
     * 
     * @param state The zoom state
     */
    public void setZoomState(ZoomState state) {
        if (mState != null) {
            mState.deleteObserver(this);
        }

        mState = state;
        mState.addObserver(this);

        invalidate();
    }

    // Private methods

    private void calculateAspectQuotient() {
        if (mBitmap != null) {
            mAspectQuotient = (((float)mBitmap.getWidth()) / mBitmap.getHeight())
                    / (((float)getWidth()) / getHeight());
        }
    }

    // Superclass overrides

    @Override
    protected void onDraw(Canvas canvas) {
        if (mBitmap != null && mState != null) {
            final int viewWidth = getWidth();
            final int viewHeight = getHeight();
            final int bitmapWidth = mBitmap.getWidth();
            final int bitmapHeight = mBitmap.getHeight();

            final float panX = mState.getPanX();
            final float panY = mState.getPanY();
            final float zoomX = mState.getZoomX(mAspectQuotient) * viewWidth / bitmapWidth;
            final float zoomY = mState.getZoomY(mAspectQuotient) * viewHeight / bitmapHeight;

            Log.i("onDraw", "onDraw"+SimpleSeekBarListener.f);
            // Setup source and destination rectangles
            mRectSrc.left = (int)(panX * bitmapWidth - viewWidth / (zoomX * 2));
            mRectSrc.top = (int)(panY * bitmapHeight - viewHeight / (zoomY * 2));
            mRectSrc.right = (int)(mRectSrc.left + viewWidth / zoomX);
            mRectSrc.bottom = (int)(mRectSrc.top + viewHeight / zoomY);
            mRectDst.left = getLeft();
            mRectDst.top = getTop();
            mRectDst.right = getRight();
            mRectDst.bottom = getBottom();

            // Adjust source rectangle so that it fits within the source image.
            if (mRectSrc.left < 0) {
                mRectDst.left += -mRectSrc.left * zoomX;
                mRectSrc.left = 0;
            }
            if (mRectSrc.right > bitmapWidth) {
                mRectDst.right -= (mRectSrc.right - bitmapWidth) * zoomX;
                mRectSrc.right = bitmapWidth;
            }
            if (mRectSrc.top < 0) {
                mRectDst.top += -mRectSrc.top * zoomY;
                mRectSrc.top = 0;
            }
            if (mRectSrc.bottom > bitmapHeight) {
                mRectDst.bottom -= (mRectSrc.bottom - bitmapHeight) * zoomY;
                mRectSrc.bottom = bitmapHeight;
            }

            canvas.drawBitmap(mBitmap, mRectSrc, mRectDst, mPaint);
            double i1=bitmapHeight*mAspectQuotient;
            double i2=bitmapWidth*mAspectQuotient;


            Log.v("Image Height",i1+"");
            Log.i("Image Width",i2+"");

            Paint paint = new Paint();
            paint.setColor(Color.GREEN);
            paint.setStrokeWidth(3);

            canvas.drawRect(40,40, 80*SimpleSeekBarListener.f, 80*SimpleSeekBarListener.f, paint);

        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);

        calculateAspectQuotient();
    }

    // implements Observer
    public void update(Observable observable, Object data) {
        invalidate();
    }

}

0 个答案:

没有答案