问题描述
限时送ChatGPT账号..在某些情况下,我的应用程序需要显示多个警报消息.错误消息是在启动时收集的,需要一次向用户显示一个.当第一个被确认时,应该呈现下一个.问题是,很明显,它们都试图同时执行.有没有一种聪明的方法可以同步执行此操作?下面是一些简单描述我想要做什么的代码:
In some cases my applications needs to display muliple Alert messages. Error messages are gathered on start and needs to be displayed to the user one at a time. When the first one is acknowledged, the next one should be presented. The problem is that they all try to execute at the same time, obviously. Is there a smart way to do this synchronously? Here is some code that simply describes what I want to do:
var errors : [NSError]!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let error1 = NSError(domain: "Test1", code: 1, userInfo: [NSLocalizedFailureReasonErrorKey : "Test1 reason."])
let error2 = NSError(domain: "Test2", code: 2, userInfo: [NSLocalizedFailureReasonErrorKey : "Test2 reason."])
let error3 = NSError(domain: "Test3", code: 2, userInfo: [NSLocalizedFailureReasonErrorKey : "Test3 reason."])
errors = [error1, error2, error3]
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
for error in errors {
self.showAlert(error)
}
}
func showAlert(error: NSError) {
var alert = UIAlertController(title: error.domain, message: error.localizedDescription, preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler:nil))
self.presentViewController(alert, animated: true, completion: nil)
}
推荐答案
您就快到了.拥有一个警报消息缓冲区是正确的想法.但不是立即显示所有警报,您应该将 showAlert()
调用移动到 UIAlertAction
的处理程序.因此,如果解除了一个警报,则会显示下一个警报.
You are almost there. Having a buffer of alert messages is the correct idea. But instead of showing all the alerts immediately, you should move the showAlert()
call to the handler of the UIAlertAction
. So if one alert is dismissed, the next will be shown.
像这样:
var errors : [NSError]!
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
let error1 = NSError(domain: "Test1", code: 1, userInfo: [NSLocalizedFailureReasonErrorKey : "Test1 reason."])
let error2 = NSError(domain: "Test2", code: 2, userInfo: [NSLocalizedFailureReasonErrorKey : "Test2 reason."])
let error3 = NSError(domain: "Test3", code: 2, userInfo: [NSLocalizedFailureReasonErrorKey : "Test3 reason."])
errors = [error1, error2, error3]
showError() // show an alert if errors are queued
}
func showError() {
if let error = errors.first {
let alert = UIAlertController(title: error.domain, message: error.localizedDescription, preferredStyle: .Alert)
let okayAction = UIAlertAction(title: "OK", style: .Default) { action in
self.errors.removeAtIndex(0) // remove the message of the alert we have just dismissed
self.showError() // show next alert if there are more errors queued
}
alert.addAction(okayAction)
presentViewController(alert, animated: true, completion: nil)
}
else {
println("All alerts shown")
}
}
<小时>
忠告:关闭多个警报非常烦人.也许您可以创建一个专用的全屏 viewController 来显示 UITableView 或其他内容中的所有错误消息.这当然取决于典型用户将看到的警报消息的数量.如果它经常超过三个,我会使用一个模式 UIViewController,它可以一目了然地显示所有消息.
Word of advice: Dismissing multiple alerts is very annoying. Maybe you could create a dedicated full screen viewController that shows all the error messages in a UITableView or something. This of course depends on the number of alert messages a typical user will see. If it's regularly more than three I would use a modal UIViewController which shows all messages at a glance.
这篇关于循环多个 UIAlertController 的的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
更多推荐
[db:关键词]
发布评论