从 AppDelegate 呈现 UIAlertController [英] Present UIAlertController from AppDelegate
本文介绍了从 AppDelegate 呈现 UIAlertController的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试在我的 iOS 应用程序中从 AppDelegate 呈现一个 UIAlertController
.以下是警报和当前方法.
I'm trying to present a UIAlertController
from the AppDelegate in my iOS app.
Below is the alert and the present method.
UIAlertController *alert = [UIAlertController alertControllerWithTitle:cTitle message:cMessage preferredStyle:UIAlertControllerStyleAlert];
//Configure alert and actions
[self.window.rootViewController presentViewController:alert animated:TRUE completion:nil];
但是,当我尝试显示警报时,它没有出现,我在控制台中收到以下警报.
However, when I try to present the alert, it doesn't appear and I get the following alert in the console.
Warning: Attempt to present <UIAlertController: 0x145f5d60> on <UINavigationController: 0x146590f0> whose view is not in the window hierarchy!
导致错误的原因是什么,我该如何解决?
What is causing the error and how do I fix it?
推荐答案
如果您想从 didFinishLaunchingWithOptions 启动它,也可以使用此代码.希望这会有所帮助.
You can use this code as well if you want to launch it from didFinishLaunchingWithOptions.Hope this helps.
dispatch_async(dispatch_get_main_queue(), {
let importantAlert: UIAlertController = UIAlertController(title: "Action Sheet", message: "Hello I was presented from appdelegate ;)", preferredStyle: .ActionSheet)
self.window?.rootViewController?.presentViewController(importantAlert, animated: true, completion: nil)
})
并且是最新的:
DispatchQueue.main.async {
let alert = UIAlertController(title: "Hello!", message: "Greetings from AppDelegate.", preferredStyle: .alert)
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
}
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