ANDROID笔记:圆形ImageView

public static Bitmap toRoundCorner(Bitmap bitmap, float pixels) {
        System.out.println("图片是否变成圆角模式了+++++++++++++");
        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        final RectF rectF = new RectF(rect);
        final float roundPx = pixels;

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);

        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
        System.out.println("pixels+++++++" + pixels);

        return output;
    }
}

调用方法:

ImageView imageView = (ImageView) findViewById(R.id.imageView1);
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
                R.drawable.ii);
　　　　//可以设置bitmap.getWidth()/2做半径
        imageView.setImageBitmap(toRoundCorner(bitmap,80.f));

效果: