android实现图片旋转

根据给定的源图片以及需要旋转的任意角度执行图片旋转变换。

    /*
     * 
     * @Title: bitmapRotation
     * @Description: 图片旋转
     * @param bm
     * @param orientationDegree
     * @return Bitmap
     * @throws
     */
    public Bitmap bitmapRotation(Bitmap bm, final int orientationDegree) {

        Matrix m = new Matrix();
        m.setRotate(orientationDegree, (float) bm.getWidth() / 2,
                (float) bm.getHeight() / 2);
        float targetX, targetY;
        if (orientationDegree == 90) {
            targetX = bm.getHeight();
            targetY = 0;
        } else if (orientationDegree == 270) {
            targetX = 0;
            targetY = bm.getWidth();
        } else {
            targetX = bm.getHeight();
            targetY = bm.getWidth();
        }

        final float[] values = new float[9];
        m.getValues(values);

        float x1 = values[Matrix.MTRANS_X];
        float y1 = values[Matrix.MTRANS_Y];

        m.postTranslate(targetX - x1, targetY - y1);

        Bitmap bm1 = Bitmap.createBitmap(bm.getHeight(), bm.getWidth(),
                Bitmap.Config.ARGB_8888);

        Paint paint = new Paint();
        Canvas canvas = new Canvas(bm1);
        canvas.drawBitmap(bm, m, paint);

        return bm1;
    }