Question

我想在我的webview应用程序中添加一个后退按钮。

通过UIBarButtonItem查看，我似乎无法找到后退按钮。见代码：

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let url = NSURL(string: "http://google.com")!
    webView.loadRequest(NSURLRequest(URL: url))
    webView.allowsBackForwardNavigationGestures = true

    let refresh = UIBarButtonItem(barButtonSystemItem: .Refresh, target: webView, action: #selector(webView.reload))

    let back = UIBarButtonItem(barButtonSystemItem: .Back, target: webView, action: #selector(webView.goBack))

    toolbarItems = [back, refresh]
    navigationController?.toolbarHidden = false

}

如何在工具栏中添加后退按钮？

Answer 1

我认为您忘了在UIBarbuttonItem

中添加navigationItem

因此您需要执行以下代码：

self.navigationItem.rightBarButtonItems = toolbarItems // that show two right side button.

如果你想在navigationbar显示左侧的后退按钮和右侧的刷新按钮，那么你必须是这样的代码：

 self.navigationItem.rightBarButtonItem = refresh
 self.navigationItem.leftBarButtonItem = back

这将出现在你的导航后退按钮左侧和刷新按钮右侧

所以你的代码看起来如下：

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let url = NSURL(string: "http://google.com")!
    webView.loadRequest(NSURLRequest(URL: url))
    webView.allowsBackForwardNavigationGestures = true

    let refresh = UIBarButtonItem(barButtonSystemItem: .Refresh, target: webView, action: #selector(webView.reload))

    //let back = UIBarButtonItem(barButtonSystemItem: .Back, target: webView, action: #selector(webView.goBack))

    let back = UIBarButtonItem(title: "Back",style: .Plain,target: webView,action: #selector(webView!.goBack))

   self.navigationItem.rightBarButtonItem = refresh
     self.navigationItem.leftBarButtonItem = back
    navigationController?.toolbarHidden = false

}

如果你想在leftbarbutton添加多个按钮，那么再创建一个UIBarbuttonItem对象：

let undo = UIBarButtonItem(barButtonSystemItem: .Undo, target: webView, action: #selector(webView.undo))

self.navigationItem.leftBarButtonItems = [back,undo]

将在导航栏上显示两个左按钮

UIBarButtonItem，使用Swift添加后退按钮

1 个答案: