How I can round UIImageView in UICollectionViewCell?

问题

In my UICollectionViewCell class I wrote this:

- (void)layoutSubviews {
    [super layoutSubviews];
    self.myImageView.layer.cornerRadius  = CGRectGetHeight(self.myImageView.frame) / 2;
    self.myImageView.layer.masksToBounds = YES;
}

But this does not work correctly in all cases, it appears like this:

回答1:

I faced a similar problem trying to get a collectionView inside a TableView Cell.

If you are changing your cell's model you should tell the cell to recalculate its layout so the cell changes its size and calls layoutIfNeeded.

 - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
              cellForItemAtIndexPath:(NSIndexPath *)indexPath
         UICollectionViewCell*cell = ...
         // Do your stuff here to configure the cell
         // Tell the cell to redraw its contentView        
         [cell layoutIfNeeded];
    }

来源：https://stackoverflow.com/questions/33733262/how-i-can-round-uiimageview-in-uicollectionviewcell