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c...