/////// 自适应屏幕 
_imageViewPics.contentMode = UIViewContentModeScaleAspectFit; 
        _imageViewPics.autoresizesSubviews = YES; 
        _imageViewPics.autoresizingMask = 
        UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth; 
          
          
  
///图片 截取 
            _imageViewPic.clipsToBounds = YES; 
            _imageViewPic.contentMode = UIViewContentModeCenter;