glide加载圆角图片内存抖动

用了一个网络上的圆角图片加载的工具加载圆角，事实上证明这种方式很坑。

/**

• glide Round corner function have conflict with the centercrop attribute

• @author Administrator
  */
  public class GlideRoundTransform extends BitmapTransformation {

  private static float radius = 0f;

  public GlideRoundTransform() {
  this(4);
  }

  public GlideRoundTransform(int dp) {

   radius = Resources.getSystem().getDisplayMetrics().density * dp;
  

  }

  @Override
  protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {
  Bitmap bitmap = TransformationUtils.centerCrop(pool, toTransform, outWidth, outHeight);
  return roundCrop(pool, bitmap);
  }

  private static Bitmap roundCrop(BitmapPool pool, Bitmap source) {
  if (source == null){
  return null;
  }

   Bitmap result = pool.get(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);
   if (result == null) {
       result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);
   }
  
   Canvas canvas = new Canvas(result);
   Paint paint = new Paint();
   paint.setShader(new BitmapShader(source, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
   paint.setAntiAlias(true);
   RectF rectF = new RectF(0f, 0f, source.getWidth(), source.getHeight());
   canvas.drawRoundRect(rectF, radius, radius, paint);
   return result;
  

  }

  public String getId() {
  return getClass().getName() + Math.round(radius);
  }

  @Override
  public void updateDiskCacheKey(MessageDigest messageDigest) {

  }

}

正确的方案：采用控件定义的方式。
可以看到这种方式创建了很多bitmap对象。尤其是当加载图片放在adapter的convert相关的方法里面的时候。