[英]Using UIAlertView in swift for iOS 7.1+
我有一些适用于iOS 8的代码,但不适用于iOS 7.1,我不确定这些代码对于iOS 7.1的外观是什么样
这是我目前在iOS 7.1上无法使用的功能
let alert = UIAlertController(title: "no connection", message: "dude, connect to the internet!", preferredStyle: UIAlertControllerStyle.Alert)
alert!.addAction(UIAlertAction(title: "Ok!", style: .Cancel, handler: { (ac: UIAlertAction!) -> Void in
alert?.dismissViewControllerAnimated(true, completion: nil)
}))
self.presentViewController(alert!, animated: true, completion: nil)
这是我试图让UIAlertView在iOS 7.1+上运行的方式
let alert = UIAlertView()
alert.title = "no connection"
alert.message = "dude, connect to the internet!"
alert.show()
看起来您希望UIAlertView
有一个不错的完成处理程序。 我不在乎使用它们时的委托模式,因此我想出了自己的扩展名:
// Used by objc_getAssociatedObject
private var UIAlertViewWrapperPropertyKey : UInt8 = 0
typealias AlertViewCompletionHandler = (alertView: UIAlertView, buttonIndex: Int) -> Void
extension UIAlertView
{
// MARK: - Associated Properties
private var wrapper : UIAlertViewWrapper?
{
get { return objc_getAssociatedObject(self, &UIAlertViewWrapperPropertyKey) as? UIAlertViewWrapper }
set { objc_setAssociatedObject(self, &UIAlertViewWrapperPropertyKey, newValue, objc_AssociationPolicy(OBJC_ASSOCIATION_RETAIN_NONATOMIC)) }
}
// MARK - Convenience Initializers
convenience init(title: String?, message: String?, cancelButtonTitle: String?)
{
self.init(title: title, message: message, delegate: nil, cancelButtonTitle: cancelButtonTitle)
}
convenience init(title: String?, message: String?, cancelButtonTitle: String?, otherButtonTitles: String...)
{
self.init(title: title, message: message, delegate: nil, cancelButtonTitle: cancelButtonTitle)
for buttonTitle in otherButtonTitles { self.addButtonWithTitle(buttonTitle) }
}
// MARK: - Show with Completion Handler
func showWithCompletion(_ completionHandler: AlertViewCompletionHandler? = nil)
{
self.wrapper = UIAlertViewWrapper(completionHandler: completionHandler)
self.delegate = self.wrapper
self.show()
}
// MARK: - Show Class Methods
class func showWithTitle(title: String?, message: String?, cancelButtonTitle: String?, completionHandler: AlertViewCompletionHandler? = nil)
{
showWithTitle(title, message: message, cancelButtonTitle: cancelButtonTitle, otherButtonTitles: nil, completionHandler: completionHandler)
}
class func showWithTitle(title: String?, message: String?, cancelButtonTitle: String?, otherButtonTitle: String?, completionHandler: AlertViewCompletionHandler? = nil)
{
let otherButtonTitles : [String]? = otherButtonTitle != nil ? [otherButtonTitle!] : nil
showWithTitle(title, message: message, cancelButtonTitle: cancelButtonTitle, otherButtonTitles: otherButtonTitles, completionHandler: completionHandler)
}
class func showWithTitle(title: String?, message: String?, cancelButtonTitle: String?, otherButtonTitles: [String]?, completionHandler: AlertViewCompletionHandler? = nil)
{
let alertView = UIAlertView(title: title, message: message, delegate: nil, cancelButtonTitle: cancelButtonTitle)
if let otherButtonTitles = otherButtonTitles
{
for buttonTitle in otherButtonTitles
{
alertView.addButtonWithTitle(buttonTitle)
}
}
alertView.showWithCompletion(completionHandler)
}
}
// Private class that handles delegation and completion handler (do not instantiate)
private final class UIAlertViewWrapper : NSObject, UIAlertViewDelegate
{
// MARK: - Completion Handlers
var completionHandler: AlertViewCompletionHandler?
// MARK: - Initializers
init(completionHandler: AlertViewCompletionHandler?)
{
self.completionHandler = completionHandler
}
// MARK: - UIAlertView Delegate
private func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int)
{
completionHandler?(alertView: alertView, buttonIndex: buttonIndex)
}
}
// You can use class function to call the UIAlertView
UIAlertView.showWithTitle("Hello", message: "Hello World", cancelButtonTitle: "Okay") { alertView, buttonIndex in
// Do something when the alert view is clicked
}
// Or... you can instantiate one and use the showWithCompletion method
let yesNoMaybeAlertView = UIAlertView(title: "Choice", message: "Pick one", cancelButtonTitle: "No", otherButtonTitles: "Yes", "Maybe")
yesNoMaybeAlertView.showWithCompletion { alertView, buttonIndex in
switch buttonIndex
{
case 1: println("Yes")
case 2: println("Maybe")
default: println("No")
}
}
根据Apple文档 ,UIAlertController仅在ios8或更高版本中可用。 您将需要在ios7中使用UIAlertView。
更新资料
抱歉,我不完全了解您的要求。
要构建UI,只需执行以下操作
let alert = UIAlertView(title: "no connection", message: "dude, connect to the internet!", delegate: self, cancelButtonTitle: "Ok!")
alert.show()
然后确保您在VC中实现UIAlertViewDelegate 。 以上应该自动关闭警报,但如果没有,您可以实施
alertView(_ alertView: UIAlertView,clickedButtonAtIndex buttonIndex: Int)
并从那里消除警报
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.