Android笔记（21）网络加载圆形图片

public class CircleTransform implements Transformation {
public Bitmap transform(Bitmap source) {
int size = Math.min(source.getWidth(), source.getHeight());
int x = (source.getWidth() - size) / 2;
int y = (source.getHeight() - size) / 2;
Bitmap squaredBitmap = Bitmap.createBitmap(source, x, y, size, size);
if (squaredBitmap != source) {
source.recycle();//回收垃圾
}
Bitmap bitmap = Bitmap.createBitmap(size, size, source.getConfig());
Canvas canvas = new Canvas(bitmap);
Paint paint = new Paint();
BitmapShader shader = new BitmapShader(squaredBitmap,
BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);//定义一个渲染器
paint.setShader(shader);//设置渲染器
paint.setAntiAlias(true);//设置抗拒齿，图片边缘相对清楚
float r = size / 2f;
canvas.drawCircle(r, r, r, paint);//绘制图形
squaredBitmap.recycle();
return bitmap;
}

public String key() {
return "circle";
}
}

Picasso.with(context).load("http://图片路径").transform(new CircleTransform()).into(imageView);