UIImageView的三种方式

---

UIImageView *imgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"图片"]];
    /*
     UIViewContentModeScaleToFill,
     UIViewContentModeScaleAspectFit,      // contents scaled to fit with fixed aspect. remainder is transparent
     UIViewContentModeScaleAspectFill,
     */
    imgView.contentMode = UIViewContentModeScaleAspectFit;

• UIViewContentModeScaleToFill：填充
• UIViewContentModeScaleAspectFit：适应
• Scale:比例
  Aspect：方向