ios - 去掉导航栏下的细线

Question

我想要实现的效果是:

我的应用的当前状态是:

这是我的 View Controller 的设置。我在导航栏下面放了一个工具栏。然后，我将工具栏的委托(delegate)设置为导航栏。我已经阅读了几篇关于此的文章。提供的一种解决方案是:

navigationController?.navigationBar.shadowImage = UIImage();
navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: .Default)

但是这样会导致导航栏变白，失去效果。所以我从这篇文章 ( UISegmentedControl below UINavigationbar in iOS 7 ) 中得到了以下代码:

    @IBOutlet weak var toolbar: UIToolbar!
    var hairLine: UIView = UIView()
    override func viewDidLoad() {
        super.viewDidLoad()
        doneButton.enabled = false

        for parent in self.navigationController!.navigationBar.subviews {
            for childView in parent.subviews {
                if childView is UIImageView && childView.bounds.size.width == self.navigationController!.navigationBar.frame.size.width {
                    hairLine = childView
                    print(hairLine.frame)
                }
            }
        }
    }

    func removeHairLine(appearing: Bool) {
        var hairLineFrame = hairLine.frame
        if appearing {
            hairLineFrame.origin.y += toolbar.bounds.size.height
        } else {
            hairLineFrame.origin.y -= toolbar.bounds.size.height
        }
        hairLine.frame = hairLineFrame
        print(hairLine.frame)
    }

    override func viewWillAppear(animated: Bool) {
        removeHairLine(true)
    }

    override func viewWillDisappear(animated: Bool) {
        removeHairLine(true)
    }

然而，这段代码在 View 完全加载之前删除了细线，但是当 View 加载时，它又出现了。有什么解决办法吗？

Answer 1

我在这个网站上找到了解决方案，但不记得确切的位置。

objective-C :

@interface YourViewController () {
  UIImageView *navBarHairlineImageView;
}

- (void)viewWillAppear:(BOOL)animated {
  [super viewWillAppear:animated];
  navBarHairlineImageView = [self findHairlineImageViewUnder:self.navigationController.navigationBar];
  navBarHairlineImageView.hidden = YES;
}

- (UIImageView *)findHairlineImageViewUnder:(UIView *)view {
  if ([view isKindOfClass:UIImageView.class] && view.bounds.size.height <= 1.0) {
    return (UIImageView *)view;
  }
  for (UIView *subview in view.subviews) {
      UIImageView *imageView = [self findHairlineImageViewUnder:subview];
      if (imageView) {
          return imageView;
      }
  }
  return nil;
}

swift :

class YourViewController: UIViewController {
    var navBarLine: UIImageView?

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        navBarLine = findHairlineImageViewUnderView(self.navigationController?.navigationBar)
        navBarLine?.hidden = true
    }

    func findHairlineImageViewUnderView(view: UIView?) -> UIImageView? {
        if view.isKindOfClass(UIImageView.classForCoder()) && view.bounds.height <= 1 {
            return view as? UIImageView
        }
        for subview in view.subviews {
            if let imgView = findHairlineImageViewUnderView(subview) {
                return imgView
            }
        }
        return nil
    }
}