@Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //畫當前圖片
        camera.save();
        camera.rotateX(0);
        camera.getMatrix(matrix);
        camera.restore();

        matrix.preTranslate(-width, 0);
        matrix.postTranslate(width, offsetY);

        canvas
 
.drawBitmap(currentBitmap, matrix, null);

        //畫下一張圖片
        camera.save();
        camera.rotateX(0);
        camera.getMatrix(matrix);
        camera.restore();

        matrix.preTranslate(-width , -height);
        matrix.postTranslate(width, offsetY);
        canvas.drawBitmap(nextBitmap, matrix
 
, null);

    }

圖片縮放

private Bitmap scaleBitmap(Bitmap bitmap) {
        int originHeight = bitmap.getHeight();
        Log.d("originHeight", originHeight + "");
        int originWidth = bitmap.getWidth();
        float scaleWidth = ((float) width)/ originWidth;
        float scaleHeight = ((float
 
) height)/ originHeight;
        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);
        return Bitmap.createBitmap(bitmap, 0, 0, originWidth, originHeight, matrix, false);
    }

屬性動畫

 public void changePic(Bitmap bitmap) {
        currentBitmap = nextBitmap;
        nextBitmap = scaleBitmap(bitmap);
        ValueAnimator animator = ObjectAnimator.ofFloat(0, height);
        animator.setDuration(1000);
        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                offsetY = (float) animation.getAnimatedValue();
                postInvalidate();
            }
        });
        animator.start();
    }