更新到Xcode 9后导航栏按钮中没有渲染图像

Question

我在UIViewController的导航栏的右侧有两个UIButton，UIbuttons有图像。该应用程序工作正常，直到它在Xcode 8中运行，但是当我更新Xcode 9时，它不是呈现，而是整个导航栏。 在Xcode中8是

但更新到Xcode中9后，它看起来像这样

我的代码来设置导航栏是...

func setUpNavBar(){ 
    self.navigationController?.navigationBar.isTranslucent = false 
    self.navigationItem.setHidesBackButton(true, animated: true) 


    let notificationBtn = UIButton(type: .custom) 
    notificationBtn.setImage(UIImage(named: "notificationIcon"), for: .normal) 
    notificationBtn.frame = CGRect(x: 0, y: 0, width: 35, height: 35) 
    notificationBtn.addTarget(self, action: #selector(HomeViewController.notificationClicked), for: .touchUpInside) 
    let item1 = UIBarButtonItem(customView: notificationBtn) 

    let profileBtn = UIButton(type: .custom) 
    profileBtn.setImage(UIImage(named: "user_profile"), for: .normal) 
    profileBtn.frame = CGRect(x: 0, y: 0, width: 35, height: 35) 
    profileBtn.addTarget(self, action: #selector(HomeViewController.ProfileClicked), for: .touchUpInside) 
    let item2 = UIBarButtonItem(customView: profileBtn) 
    self.navigationItem.setRightBarButtonItems([item1,item2], animated: true) 

} 

我很困惑它为什么会发生。

Answer 1

在iOS 11你需要添加/身高的一系列约束和与UIButton

对于notificationBtn

let widthConstraint = notificationBtn.widthAnchor.constraint(equalToConstant: 35) 
let heightConstraint = notificationBtn.heightAnchor.constraint(equalToConstant: 35) 
heightConstraint.isActive = true 
widthConstraint.isActive = true 

为profileBtn应用一样了。