UIBarButtonItem 给我错误的 popoverPresentationController 框架

Question

我有一个工具栏，左上角有一个 UIBarButtomItem，标签为 Admin

我需要在点击它时显示一个弹出窗口，但它出现在错误的位置，它出现在屏幕的左上角：

这是打开弹窗的函数：

// this IBAction is assigned only to the Admin bar button item
@IBAction func openAdmin(sender: UIBarButtonItem) {
    let alertController = UIAlertController(title: nil, message: "Elige una opción", preferredStyle: .ActionSheet)

    // action button initializations... ... ...

    let barButtonItemSize = sender.valueForKey("view")

    alertController.popoverPresentationController?.sourceView = self.view
    alertController.popoverPresentationController?.sourceRect = barButtonItemSize!.frame

    presentViewController(alertController, animated: true, completion: nil)
}

当我触摸管理栏按钮时，我还在控制台上收到此警告：

Snapshotting a view that has not been rendered results in an empty snapshot. Ensure your view has been rendered at least once before snapshotting or snapshot after screen updates

我做错了什么？或者我需要做什么才能在管理员顶部显示弹出窗口？

Answer 1

替换

alertController.popoverPresentationController?.sourceView = self.view
alertController.popoverPresentationController?.sourceRect = barButtonItemSize!.frame

和

alertController.popoverPresentationController?.sourceView = sender
alertController.popoverPresentationController?.barButtonItem = sender

UIBarButtonItem 给我错误的 popoverPresentationController 框架

UIBarButtonItem gives me wrong frame for popoverPresentationController

ios

swift

uibarbuttonitem

uipopover