无法将 UIBarButtonItem 添加到 UINavigationController 中的工具栏

Question

我尝试将UIBarButtonItem添加到UINavigationController的工具栏，但它没有显示任何按钮，并且在调试时发现_toolbar数组为空.

override func viewDidLoad() {
        var default_title = ["A","B"," C","D"]
        var items: NSArray = NSArray()
        for title in default_title
        {
            items.arrayByAddingObject(UIBarButtonItem(title: title, style: UIBarButtonItemStyle.Bordered, target: self, action: ""))
        }

        self.setToolbarItems(items as [AnyObject], animated: true)
        self.setToolbarHidden(false, animated: false)
}

Answer 1

我发现问题是 items 应该是 Array<UIBarButtonItem>。

代码：

override func viewDidLoad() {
    var default_title = ["A","B"," C","D"]
        var items: Array<UIBarButtonItem> = []
        for title in default_title
        {
            items.append(UIBarButtonItem(title: title, style: UIBarButtonItemStyle.Bordered, target: self, action: ""))
        }

        self.setToolbarItems(items as [AnyObject], animated: true)
        self.setToolbarHidden(false, animated: false)
}