Barbuttonitems和标题未出现在iOS 11中

Question

由于iOS 11和Xcode 9 BarbuttonItems和标题不再可见。我是否试图添加这样的自定义视图都没关系：

let backButton = UIButton.init(frame: CGRect(x: 0, y: 0, width: 180, height: 32))
        backButton.setImage(UIImage(named: "back_icon")?.withRenderingMode(.alwaysTemplate), for: .normal)
        backButton.tintColor = UIColor.white
        backButton.addTarget(self, action: #selector(backAction), for: .touchUpInside)
        backButton.backgroundColor = UIColor.clear
        backButton.titleLabel?.font = UIFont(name: SWMainHelper.sharedInstance.mediumFont, size: 18)
        backButton.setTitleColor(UIColor.white, for: .normal)
        backButton.setTitle("Go back", for: .normal)
        backButton.sizeToFit()
        backButton.titleEdgeInsets = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 0)
        backButton.frame.size.width += 16
        let negativeButtonSpace = UIBarButtonItem(barButtonSystemItem: .fixedSpace, target: nil, action: nil)
        negativeButtonSpace.width = -16
        self.navigationItem.setLeftBarButtonItems([negativeButtonSpace, UIBarButtonItem(customView: backButton)], animated: true)

或仅像这样的标准uibarbuttonems：

let add = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
        add.tintColor = UIColor.white
        let play = UIBarButtonItem(title: "Play", style: .plain, target: self, action: #selector(playTapped))
        play.tintColor = UIColor.white
        navigationItem.rightBarButtonItems = [add, play]

使用Xcode 8一切正常。

Answer 1

此问题是在用Xcode 9编译时出现的，因为现在UIBarButtonItem也使用autoLayput。below是使其正常工作的代码。

UIButton *leftCustomButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 35, 100)];
        [leftCustomButton.widthAnchor constraintEqualToConstant:100].active = YES;
        [leftCustomButton.heightAnchor constraintEqualToConstant:35].active = YES;
        [leftCustomButton setTitle:@"TEST" forState:UIControlStateNormal];
        [leftCustomButton.titleLabel setFont:[UIFont boldSystemFontOfSize:16.0]];
        [leftCustomButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        UIBarButtonItem * leftButtonItem =[[UIBarButtonItem alloc] initWithCustomView:leftCustomButton];        
        [self.navigationItem setRightBarButtonItems:@[leftButtonItem]];

Answer 2

我在更新到xCode9 IDE时也有相同的问题。我能够使用UINavigationBar.appearance：

解决此问题

    let buttonItem = UIButton.appearance(whenContainedInInstancesOf: [UINavigationBar.self])
    buttonItem.setTitleColor(.black, for: .normal)
    buttonItem.setTitleColor(.gray, for: .disabled)

Answer 3

我也有同样的问题，并且没有上述问题。我要做的就是在titleView上设置width，一切都很好！

编辑：

每个UIViewController都有navigationItem属性，每个navigationItem都有一个可选的titleView。

参考：https：//developer.apple.com/documentation/uikit/uinavigationitem/1624935-titleview

就我而言，我正在使用自定义titleView，我认为这是问题的原因，因为Apple更改了API以支持新的导航栏布局。