AVAudioSession.Notifications.ObserveRouteChange 方法

定義

命名空間:

AVFoundation

組件:

Xamarin.iOS.dll

多載

ObserveRouteChange(EventHandler<AVAudioSessionRouteChangeEventArgs>)	常數的 RouteChangeNotification 強型別通知。
ObserveRouteChange(NSObject, EventHandler<AVAudioSessionRouteChangeEventArgs>)	常數的 RouteChangeNotification 強型別通知。

ObserveRouteChange(EventHandler<AVAudioSessionRouteChangeEventArgs>)

常數的 RouteChangeNotification 強型別通知。

public static Foundation.NSObject ObserveRouteChange (EventHandler<AVFoundation.AVAudioSessionRouteChangeEventArgs> handler);

static member ObserveRouteChange : EventHandler<AVFoundation.AVAudioSessionRouteChangeEventArgs> -> Foundation.NSObject

參數

handler

EventHandler<AVAudioSessionRouteChangeEventArgs>

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

下列範例示範開發人員如何在其程式碼中使用此方法：

//
// Lambda style
//

// listening
notification = AVAudioSession.Notifications.ObserveRouteChange ((sender, args) => {
    /* Access strongly typed args */
    Console.WriteLine ("Notification: {0}", args.Notification);

    Console.WriteLine ("Reason", args.Reason);
    Console.WriteLine ("PreviousRoute", args.PreviousRoute);
});

// To stop listening:
notification.Dispose ();

//
//Method style
//
NSObject notification;
void Callback (object sender, AVFoundation.AVAudioSessionRouteChangeEventArgs args)
{
    // Access strongly typed args
    Console.WriteLine ("Notification: {0}", args.Notification);

    Console.WriteLine ("Reason", args.Reason);
    Console.WriteLine ("PreviousRoute", args.PreviousRoute);
}

void Setup ()
{
    notification = AVAudioSession.Notifications.ObserveRouteChange (Callback);
}

void Teardown ()
{
    notification.Dispose ();
}

ObserveRouteChange(NSObject, EventHandler<AVAudioSessionRouteChangeEventArgs>)

常數的 RouteChangeNotification 強型別通知。

public static Foundation.NSObject ObserveRouteChange (Foundation.NSObject objectToObserve, EventHandler<AVFoundation.AVAudioSessionRouteChangeEventArgs> handler);

static member ObserveRouteChange : Foundation.NSObject * EventHandler<AVFoundation.AVAudioSessionRouteChangeEventArgs> -> Foundation.NSObject

參數

objectToObserve

NSObject

要觀察的特定物件。

handler

EventHandler<AVAudioSessionRouteChangeEventArgs>

在發生通知時回應通知的處理常式。

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 RouteChangeNotification 通知。

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

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

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