NSExtensionContext.Notifications.ObserveHostDidEnterBackground 方法
定义
重要
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重载
ObserveHostDidEnterBackground(EventHandler<NSNotificationEventArgs>)
常量的强类型通知 HostDidEnterBackgroundNotification 。
public static Foundation.NSObject ObserveHostDidEnterBackground (EventHandler<Foundation.NSNotificationEventArgs> handler);static member ObserveHostDidEnterBackground : EventHandler<Foundation.NSNotificationEventArgs> -> Foundation.NSObject参数
- handler
- EventHandler<NSNotificationEventArgs>
发布通知时调用的方法。
返回
令牌对象，可用于通过释放通知或将其传递给来停止接收通知 RemoveObservers(IEnumerable<NSObject>)
注解
此方法可用于订阅 HostDidEnterBackgroundNotification 通知。
// Listen to all notifications posted for any object
var token = NSExtensionContext.Notifications.ObserveHostDidEnterBackground ((notification) => {
Console.WriteLine ("Observed HostDidEnterBackgroundNotification!");
};
// Listen to all notifications posted for a single object
var token = NSExtensionContext.Notifications.ObserveHostDidEnterBackground (objectToObserve, (notification) => {
Console.WriteLine ($"Observed HostDidEnterBackgroundNotification for {nameof (objectToObserve)}!");
};
// Stop listening for notifications
token.Dispose ();
适用于
ObserveHostDidEnterBackground(NSObject, EventHandler<NSNotificationEventArgs>)
常量的强类型通知 HostDidEnterBackgroundNotification 。
public static Foundation.NSObject ObserveHostDidEnterBackground (Foundation.NSObject objectToObserve, EventHandler<Foundation.NSNotificationEventArgs> handler);static member ObserveHostDidEnterBackground : Foundation.NSObject * EventHandler<Foundation.NSNotificationEventArgs> -> Foundation.NSObject参数
- objectToObserve
- NSObject
要观察的对象。
- handler
- EventHandler<NSNotificationEventArgs>
发布通知时调用的方法。
返回
令牌对象，可用于通过释放通知或将其传递给来停止接收通知 RemoveObservers(IEnumerable<NSObject>)
注解
此方法可用于订阅 HostDidEnterBackgroundNotification 通知。
// Listen to all notifications posted for any object
var token = NSExtensionContext.Notifications.ObserveHostDidEnterBackground ((notification) => {
Console.WriteLine ("Observed HostDidEnterBackgroundNotification!");
};
// Listen to all notifications posted for a single object
var token = NSExtensionContext.Notifications.ObserveHostDidEnterBackground (objectToObserve, (notification) => {
Console.WriteLine ($"Observed HostDidEnterBackgroundNotification for {nameof (objectToObserve)}!");
};
// Stop listening for notifications
token.Dispose ();