如何以编程方式在导航栏下方添加视图?

问题描述

我试图将视图添加到UINavigationController，其顶部与导航栏的底部对齐.

I'm trying to add a view to a UINavigationController with its top aligned with the navigation bar's bottom.

我尝试通过将以下内容添加到我的UINavigationController子类中来使用约束:

I tried using constraints by adding the following to my UINavigationController subclass:

override func viewDidAppear(_ animated: Bool) {
           self.label = UILabel()
    self.label?.translatesAutoresizingMaskIntoConstraints = false
    self.label?.backgroundColor = UIColor.red
    self.label?.text = "label text"
    self.view.addSubview(self.label!)
    let horConstraint = NSLayoutConstraint(item: label!, attribute: .top, relatedBy: .equal,
                                           toItem: topLayoutGuide, attribute: .bottom,
                                           multiplier: 1.0, constant: 0.0)
    let widthConstr = NSLayoutConstraint(item: label!, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 100)

    let heightConstr = NSLayoutConstraint(item: label!, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 100)
    view.addConstraints([horConstraint, widthConstr, heightConstr])
}

结果如下:

然后我尝试通过设置子视图的框架:

And I tried by setting the frame of my subview:

override func viewDidAppear(_ animated: Bool) {

    self.label = UILabel(frame: CGRect(x: 0, y: navigationBar.frame.height, width: 300, height: 100))
    self.label?.translatesAutoresizingMaskIntoConstraints = false
    self.label?.backgroundColor = UIColor.red
    self.label?.text = "label text"
    self.view.addSubview(self.label!)

}

这出来了:

在两种情况下，我的标签都覆盖了导航栏的一部分.我该如何解决?

In both cases my label covers part of the navigation bar. How to I fix this?

推荐答案

状态栏的高度为20.分配标签的y时，还应考虑状态栏.您的viewDidAppear应该是

Height of status bar is 20.You should consider status bar also while assigning y of your label. Your viewDidAppear should be

override func viewDidAppear(_ animated: Bool) {

    self.label = UILabel(frame: CGRect(x: 0, y: navigationBar.frame.height+20, width: navigationBar.frame.width, height: 100))
    self.label?.translatesAutoresizingMaskIntoConstraints = false
    self.label?.backgroundColor = UIColor.red
    self.label?.text = "label text"
    self.view.addSubview(self.label!)
 }

希望它会有所帮助.祝您编码愉快！

Hope it helps. Happy Coding!!

这篇关于如何以编程方式在导航栏下方添加视图?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！