Zendesk iOS：Messaging实例嵌入导航控制器后UIBarButtonItem不显示

我之前也碰到过一模一样的问题！Zendesk的Messaging视图控制器内部会自己创建并管理导航栏组件，直接给它的navigationItem设置按钮大概率会被覆盖或者根本不生效，这里给你几个经过验证的可行方案：

方案1：给导航控制器的顶层视图控制器绑定按钮 #

既然我们是用UINavigationController包裹Zendesk的VC，不如直接操作导航控制器的topViewController，避开Zendesk内部的导航栏干扰：

if let zendeskSupportVC = ZendeskController().createInstance() {
    let navigationController = UINavigationController(rootViewController: zendeskSupportVC)
    // 直接给导航控制器的顶层VC设置标题和按钮
    navigationController.topViewController?.title = NSLocalizedString("Contact Us", comment: "Contact Us")
    let dismissBtn = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(dismissSupportPage))
    navigationController.topViewController?.navigationItem.rightBarButtonItem = dismissBtn
    self.present(navigationController, animated: true)
}

不过这个方法偶尔会因为Zendesk内部的视图生命周期触发而失效，要是碰到这种情况，可以试试方案2。

方案2：利用Zendesk官方的UI配置接口 #

Zendesk的Messaging SDK其实提供了自定义导航栏的配置项，我们可以在构建UI的时候就把按钮配置进去，从根源上避免被覆盖：

先修改你的createInstance方法，给MessagingConfiguration添加导航栏配置：

func createInstance() -> UIViewController? {
    do {
        let requestConfiguration = RequestUiConfiguration()
        var messagingConfiguration = MessagingConfiguration()
        
        // 配置导航栏标题和右侧按钮
        let navConfig = NavigationBarConfiguration(
            title: NSLocalizedString("Contact Us", comment: "Contact Us"),
            rightBarButtonItems: [UIBarButtonItem(barButtonSystemItem: .done, target: nil, action: nil)]
        )
        messagingConfiguration.navigationBarConfiguration = navConfig
        
        let answerBotEngine = try AnswerBotEngine.engine()
        let supportEngine = try SupportEngine.engine()
        let chatEngine = try ChatEngine.engine()
        
        let zendeskVC = try Messaging.instance.buildUI(
            engines: [answerBotEngine, supportEngine, chatEngine],
            configs: [messagingConfiguration, requestConfiguration]
        )
        return zendeskVC
    } catch let error {
        print("Error launching Zendesk: \(error)")
        return nil
    }
}

这里要注意：配置里的按钮没法直接绑定target和action，我们可以在呈现后延迟一点，找到按钮再绑定：

@objc func dismissSupportPage() {
    self.dismiss(animated: true)
}

// 呈现时绑定按钮事件
if let zendeskSupportVC = ZendeskController().createInstance() {
    let navigationController = UINavigationController(rootViewController: zendeskSupportVC)
    self.present(navigationController, animated: true) {
        // 延迟确保视图加载完成
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
            if let doneBtn = navigationController.topViewController?.navigationItem.rightBarButtonItems?.first {
                doneBtn.target = self
                doneBtn.action = #selector(self.dismissSupportPage)
            }
        }
    }
}

方案3：自定义导航控制器子类（最稳定） #

如果前两个方案都不稳，那可以创建一个自定义导航控制器子类，在viewDidAppear里强制设置导航栏按钮，确保不会被Zendesk的内部逻辑打断：

class ZendeskNavigationController: UINavigationController {
    weak var dismissDelegate: UIViewController?
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        // 强制覆盖导航栏配置
        self.topViewController?.title = NSLocalizedString("Contact Us", comment: "Contact Us")
        let dismissBtn = UIBarButtonItem(barButtonSystemItem: .done, target: dismissDelegate, action: #selector(dismissDelegate?.dismissSupportPage))
        self.topViewController?.navigationItem.rightBarButtonItem = dismissBtn
    }
}

然后用这个子类来呈现Zendesk的VC：

if let zendeskSupportVC = ZendeskController().createInstance() {
    let navController = ZendeskNavigationController(rootViewController: zendeskSupportVC)
    navController.dismissDelegate = self
    self.present(navController, animated: true)
}

我当时踩坑后用的是方案3，稳定性拉满，完全不会被Zendesk的内部更新干扰，你可以根据自己的场景选合适的方案。

内容的提问来源于stack exchange，提问作者danchez