新增 Audio.OnAudioSessionRouteChangedEvent，用于监听音频设备变更事件。

Author: Aaron8052

Plugins/CS/Audio.cs

@@ -8,13 +8,33 @@ namespace iOSNativePlugin
 {
     public static class Audio
     {
+        [DllImport("__Internal")] static extern float Audio_Init(Action OnAudioSessionRouteChangedCallback);
         [DllImport("__Internal")] static extern float Audio_SystemVolume();
         [DllImport("__Internal")] static extern double Audio_InputLatency();
         [DllImport("__Internal")] static extern double Audio_OutputLatency();
         [DllImport("__Internal")] static extern double Audio_SampleRate();
         [DllImport("__Internal")] static extern bool Audio_IsBluetoothHeadphonesConnected();
         [DllImport("__Internal")] static extern void Audio_SetAudioExclusive(bool exclusive);
 
+        static Action onAudioSessionRouteChangedEvent;
+
+        public static event Action OnAudioSessionRouteChangedEvent
+        {
+            add
+            {
+                Audio_Init(OnAudioSessionRouteChanged);
+                onAudioSessionRouteChangedEvent += value;
+            }
+            remove => onAudioSessionRouteChangedEvent -= value;
+        }
+
+
+        [MonoPInvokeCallback(typeof(Action))]
+        static void OnAudioSessionRouteChanged()
+        {
+            onAudioSessionRouteChangedEvent?.Invoke();
+        }
+
         /// <summary>
         /// 当前系统音量
         /// <para>https://developer.apple.com/documentation/avfaudio/avaudiosession/1616533-outputvolume?language=objc</para>

Plugins/Native/Headers/Audio.h

@@ -2,6 +2,7 @@
 
 @interface Audio : NSObject
 
++(void)Init:(Action)OnAudioSessionRouteChangedCallback;
 +(float)SystemVolume;
 +(double)InputLatency;
 +(double)OutputLatency;
@@ -13,6 +14,10 @@
 
 extern "C"
 {
+    void Audio_Init(Action OnAudioSessionRouteChangedCallback)
+    {
+        [Audio Init:OnAudioSessionRouteChangedCallback];
+    }
     float Audio_SystemVolume()
     {
         return [Audio SystemVolume];

Plugins/Native/Implementations/Audio.mm

@@ -3,6 +3,28 @@
 
 @implementation Audio
 
+static Action onAudioSessionRouteChangedEvent;
+static BOOL inited;
+
++(void)Init:(Action)OnAudioSessionRouteChangedCallback
+{
+    if(inited)
+        return;
+    onAudioSessionRouteChangedEvent = OnAudioSessionRouteChangedCallback;
+    [[NSNotificationCenter defaultCenter] addObserver: [Audio class]
+                                             selector: @selector(OnAudioSessionRouteChanged:)
+                                                 name: AVAudioSessionRouteChangeNotification
+                                               object: nil];
+    inited = YES;
+}
+
++(void)OnAudioSessionRouteChanged:(NSNotification *)notification
+{
+    if(onAudioSessionRouteChangedEvent != nil)
+        onAudioSessionRouteChangedEvent();
+}
+
+
 +(float)SystemVolume
 {
     return [[AVAudioSession sharedInstance] outputVolume];

Plugins/Native/Utils.mm

@@ -36,7 +36,7 @@ static void LOG(NSString* log){
     return date;
 }
 
-
+typedef void (*Action)();
 typedef void (*SaveImageToAlbumCallback)(bool);
 typedef void (*ShareCloseCallback)();
 typedef void (*FileSavedCallback)(bool);