Question

IOS 11导致主标签从顶部移动一点而不是保持在顶部。问题只出现在IOS 11上。对于不同的IOS，一切看起来都不错。

带有设置标题的代码示例：

    private func setHeader(agentName: String = "", isTyping: Bool = false) -> Void {
    if (agentName.isEmpty) {
        self.containerViewController?.navigationItem.titleView = nil
    } else {
        let headerView: UIView = {
            let rect = CGRect(x: 0, y: 0, width: 320, height: 44)
            let uiview = UIView(frame: rect)

            return uiview
        }()


        let headerLabel: UILabel = {
            let label = UILabel(frame: CGRect(x: 0, y: 0, width: headerView.frame.width, height: 20))
            label.font = UIFont.systemFont(ofSize: 18)
            label.textAlignment = .center
            label.translatesAutoresizingMaskIntoConstraints = false
            return label
        }()

        let subheaderLabel: UILabel = {
            let label = UILabel(frame: CGRect(x: 0, y: 0, width: headerView.frame.width, height: 12))
            label.font = UIFont.systemFont(ofSize: 12)
            label.translatesAutoresizingMaskIntoConstraints = false
            label.text = self.title
            return label
        }()


        headerView.addSubview(headerLabel)
        headerView.addSubview(subheaderLabel)

        let viewsDictionary = ["header": headerLabel, "subheader": subheaderLabel]
        headerView.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[header]|", options: NSLayoutFormatOptions(), metrics: nil, views: viewsDictionary))
        headerView.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[subheader]|", options: NSLayoutFormatOptions(), metrics: nil, views: viewsDictionary))
        headerView.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[header(20)]-[subheader]", options: [], metrics: nil, views: viewsDictionary))

        self.containerViewController?.navigationItem.titleView = headerView

    }
}

Answer 1

从iOS 11开始，现在使用自动布局布置添加到工具栏的视图。您应该在headerView上添加大小限制。例如：

headerView.widthAnchor.constraintEqualToConstant(320.0).isActive = true
headerView.heightAnchor.constraintEqualToConstant(44.0).isActive = true

否则，自动布局将使用标题视图的内在内容大小，这可能与您的预期不同。

有关详细信息，请参阅WWDC 2017会话Updating your app for iOS 11。

Answer 2

@beyowulf说你必须添加大小限制。我认为在你的情况下添加NULL是可以的：

SELECT CONCAT('ID:', [ID], ', Key:', [Key], ', Value:', [Value]);

仅限IOS 11：顶部的导航栏标签

2 个答案: