UIAlertController 崩溃错误 [重复]

Question

这是我的代码

let selectRoute = UIAlertController(title: "Select a Route", message: "Please select the route you want to create your trip on", preferredStyle: .actionSheet)

    let route1 = UIAlertAction(title: "Route 1", style: .default) { (action) in
        self.reminder()
        self.routeID = 1
        self.tableView.reloadData()
    }

    let route2 = UIAlertAction(title: "Route 2", style: .default) { (action) in

    }

    selectRoute.addAction(route1)
    selectRoute.addAction(route2)

    if let popoverPresentationController = selectRoute.popoverPresentationController {
        popoverPresentationController.sourceView = self.view
        popoverPresentationController.sourceRect = self.view.bounds
    }

    self.present(selectRoute, animated: true, completion: nil)

当我运行这个时，actionSheet 只是出现在导航控制器上，非常小，有人知道解决方法吗？

Answer 1

在 iPad 上，警报将使用 UIPopoverPresentationController 显示为弹出框，它需要您使用 sourceView 和 sourceRect 或 barButtonItem 为弹出框的呈现定义一个锚点。

要支持 iPad，请包含以下代码：

alertController.popoverPresentationController?.sourceView = self.view
alertController.popoverPresentationController?.sourceRect = self.myButton.frame
self.presentViewController(alertController, animated: true, completion: nil)

这是一个例子： 假设您有一个按钮，并且您将在按钮下方显示警报控制器：

@IBOutlet weak var myBtn: UIButton!

let alertController = UIAlertController(title: "title :)", message:"message...", preferredStyle: .actionSheet)
let defaultAction = UIAlertAction(title: "cancel", style: .cancel, handler: nil)

let deleteAction = UIAlertAction(title: "delete", style: .destructive) { (action: UIAlertAction) in
        //Do something
    }

let addAction = UIAlertAction(title: "...", style: .default) { (action) in
        //do something
    }

alertController.addAction(addAction)
alertController.addAction(deleteAction)
alertController.addAction(defaultAction)

alertController.popoverPresentationController?.sourceRect = self.myBtn.frame
alertController.popoverPresentationController?.sourceView = self.view
self.present(alertController, animated: true, completion: nil)

如果您在用户对 UITableView 中的单元格进行选择后显示操作表。您可以使用此代码：

alertController.popoverPresentationController.sourceView = cell
alertController.popoverPresentationController.sourceRect = cell.bounds