UIBarItem.Notifications.ObserveFocusedElementKey 方法

定義

命名空間:

UIKit

組件:

Xamarin.iOS.dll

多載

ObserveFocusedElementKey(EventHandler<NSNotificationEventArgs>)	P：UIKit.UIBarItem.FocusedElementKeyNotification常數的強型別通知。
ObserveFocusedElementKey(NSObject, EventHandler<NSNotificationEventArgs>)	P：UIKit.UIBarItem.FocusedElementKeyNotification常數的強型別通知。

ObserveFocusedElementKey(EventHandler<NSNotificationEventArgs>)

P：UIKit.UIBarItem.FocusedElementKeyNotification常數的強型別通知。

public static Foundation.NSObject ObserveFocusedElementKey (EventHandler<Foundation.NSNotificationEventArgs> handler);

static member ObserveFocusedElementKey : EventHandler<Foundation.NSNotificationEventArgs> -> Foundation.NSObject

參數

handler

EventHandler<NSNotificationEventArgs>

張貼通知時叫用的方法。

傳回

NSObject

權杖物件，可用來停止接收通知，方法是處置通知或傳遞至 RemoveObservers(IEnumerable<NSObject>)

備註

這個方法可以用來訂閱 P：UIKit.UIBarItem.FocusedElementKeyNotification通知。

// Listen to all notifications posted for any object
var token = UIBarItem.Notifications.ObserveFocusedElementKey ((notification) => {
	Console.WriteLine ("Observed FocusedElementKeyNotification!");
};

// Listen to all notifications posted for a single object
var token = UIBarItem.Notifications.ObserveFocusedElementKey (objectToObserve, (notification) => {
	Console.WriteLine ($"Observed FocusedElementKeyNotification for {nameof (objectToObserve)}!");
};

// Stop listening for notifications
token.Dispose ();

ObserveFocusedElementKey(NSObject, EventHandler<NSNotificationEventArgs>)

P：UIKit.UIBarItem.FocusedElementKeyNotification常數的強型別通知。

public static Foundation.NSObject ObserveFocusedElementKey (Foundation.NSObject objectToObserve, EventHandler<Foundation.NSNotificationEventArgs> handler);

static member ObserveFocusedElementKey : Foundation.NSObject * EventHandler<Foundation.NSNotificationEventArgs> -> Foundation.NSObject

參數

objectToObserve

NSObject

要觀察的物件。

handler

EventHandler<NSNotificationEventArgs>

張貼通知時叫用的方法。

傳回

NSObject

權杖物件，可用來停止接收通知，方法是處置通知或傳遞至 RemoveObservers(IEnumerable<NSObject>)

備註

這個方法可以用來訂閱 P：UIKit.UIBarItem.FocusedElementKeyNotification通知。

// Listen to all notifications posted for any object
var token = UIBarItem.Notifications.ObserveFocusedElementKey ((notification) => {
	Console.WriteLine ("Observed FocusedElementKeyNotification!");
};

// Listen to all notifications posted for a single object
var token = UIBarItem.Notifications.ObserveFocusedElementKey (objectToObserve, (notification) => {
	Console.WriteLine ($"Observed FocusedElementKeyNotification for {nameof (objectToObserve)}!");
};

// Stop listening for notifications
token.Dispose ();