info 加相册权限
UIImage *iamge =[self screenShotView:self.scrollView];
UIImageWriteToSavedPhotosAlbum(iamge, self, @selector(image:didFinishSavingWithError:contextInfo:), (__bridge void *)self);

• (UIImage )screenShotView:(UIView)view{
  UIImage *image = [[UIImage alloc]init];
  CGSize size;
  size.width = SCREEN_WIDTH;
  size.height = FIT(170);
  UIGraphicsBeginImageContextWithOptions(size, false, 0.0);
  [view.layer renderInContext:UIGraphicsGetCurrentContext()];
  image = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  return image;
  }

pragma mark -- <保存到相册>

-(void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
NSString *msg = nil ;
if(error){
msg = @"保存图片失败" ;
}else{
msg = @"保存图片成功" ;
}
}