[iOs] SDWebImage 下載後 圖片上下留白

contentMode 設AspectFit

寬比高長

[self.picImageView sd_setImageWithURL:[NSURL URLWithString:url] placeholderImage:[UIImage imageNamed:@"pic_offer_n"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {

            

            double width = image.size.width;

            double height = image.size.height;

            double apect = width/height;

            double imageViewWidth = weakSelf.picImageView.frame.size.width;

            double nHeight = imageViewWidth /  apect;

            [weakSelf.picImageView.heightAnchor constraintEqualToConstant:nHeight].active = YES;

            

        }];

設定 height 的constraint，重設height