imageview显示圆形图片

需要ImageView显示圆形图片做法如下

public static Bitmap toRoundCorner(Bitmap bitmap, float ratio) {        System.out.println("图片是否变成圆形模式了+++++++++++++");        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),                bitmap.getHeight(), Bitmap.Config.ARGB_8888);        Canvas canvas = new Canvas(output);        final Paint paint = new Paint();        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());        final RectF rectF = new RectF(rect);        paint.setAntiAlias(true);        canvas.drawARGB(0, 0, 0, 0);        canvas.drawRoundRect(rectF, bitmap.getWidth() / ratio,                bitmap.getHeight() / ratio, paint);        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));        canvas.drawBitmap(bitmap, rect, rect, paint);        System.out.println("pixels+++++++" + String.valueOf(ratio));        return output;    }

出处：http://www.apkbus.com/android-123489-1-1.html