Swift之导航栏标题文字太长，导致返回按钮文字消失问题解决

import UIKit
class DetailViewController: UIViewController {
     
    override func viewDidLoad() {
        let titleView = UIView(frame: CGRectMake(0, 0, 200, 40))
        let labelForTitle = UILabel(frame: CGRectMake(0, 0, 200, 30))
        labelForTitle.font = UIFont.systemFontOfSize(17.0, weight: UIFontWeightMedium)
        labelForTitle.center = titleView.center
        labelForTitle.text = "文章列表（欢迎访问hangge.com）"
        titleView.addSubview(labelForTitle)
        self.navigationItem.titleView = titleView
    }
     
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}
功能改进：如果文字过长，label自动缩小文字大小
上面的方法会把多余的文字截断并在后面添加...。如果想让标题文字能完全显示，可以通过 adjustsFontSizeToFitWidth 属性让文本标签自动缩放文字尺寸以适应标签大小。效果图如下：

import UIKit
 
class DetailViewController: UIViewController {
     
    override func viewDidLoad() {
        let titleView = UIView(frame: CGRectMake(0, 0, 200, 40))
        let labelForTitle = UILabel(frame: CGRectMake(0, 0, 200, 30))
        labelForTitle.font = UIFont.systemFontOfSize(17.0, weight: UIFontWeightMedium)
        labelForTitle.center = titleView.center
        labelForTitle.adjustsFontSizeToFitWidth = true
        labelForTitle.text = "文章列表（欢迎访问hangge.com）"
        titleView.addSubview(labelForTitle)
        self.navigationItem.titleView = titleView
    }
     
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}