ios. 给UIView设置图片

UIImage *image = [UIImage imageNamed:@"playing"]; 
  _layerView.layer.contents = (__bridge id)image.CGImage; 
//同样可以设置显示的图片范围 
//不过此处略有不同，这里的四个值均为0-1之间；对应的依然是写x,y,widt,height
_layerView.layer.contentsCenter = CGRectMake(0.25, 0.25, 0.5, 0.5);