The sole C# example code does not compile and is invalid. about windows-dev-docs HOT 3 OPEN

	private bool DecideRedirection( string key )
	{
		bool isRedirect = false;

		// Find out what kind of activation this is.
		AppActivationArguments args = AppInstance.GetCurrent().GetActivatedEventArgs();
		ExtendedActivationKind kind = args.Kind;
		if ( kind == ExtendedActivationKind.Launch )
		{
			try
			{
				AppInstance keyInstance = AppInstance.FindOrRegisterForKey( key );

				// If we successfully registered the file name, we must be the
				// only instance running that was activated for this file.
				if ( keyInstance.IsCurrent )
				{
					// Hook up the Activated event, to allow for this instance of the app
					// getting reactivated as a result of multi-instance redirection.
					keyInstance.Activated += OnKeyInstanceActivated;
				}
				else
				{
					isRedirect = true;

					Utility.HandleWaiterInterop waiter = new HandleWaiterInterop();

					// Ensure we don't block the STA, by doing the redirect operation
					// in another thread, and using an event to signal when it has completed.
					var redirectEventHandle = HandleWaiterInterop.CreateEvent( IntPtr.Zero , true , false , null );
					if ( redirectEventHandle != IntPtr.Zero )
					{
						Task.Run( () =>
						{
							keyInstance.RedirectActivationToAsync( args ).AsTask().Wait();
							HandleWaiterInterop.SetEvent( redirectEventHandle );
						} );

						HandleWaiterInterop.WaitForHandles( new nint[] { redirectEventHandle } );
					}
				}
			}
			catch ( Exception ex )
			{
				Debug.WriteLine( $"Error getting instance information: {ex.Message}" );
			}
		}

		return isRedirect;
	}

public class HandleWaiterInterop
{
	// Import the CoWaitForMultipleObjects function from combase.dll
	[DllImport( "combase.dll" , SetLastError = true )]
	public static extern int CoWaitForMultipleObjects(
		 uint dwFlags ,
		 uint dwTimeout ,
		 uint cHandles ,
		 IntPtr pHandles ,
		 out uint lpdwIndex
	);

	[DllImport( "kernel32.dll" , SetLastError = true )]
	public static extern IntPtr CreateEvent(
		IntPtr lpEventAttributes ,
		bool bManualReset ,
		bool bInitialState ,
		string lpName
	);

	[DllImport( "kernel32.dll" , SetLastError = true )]
	public static extern bool SetEvent( IntPtr hEvent );

	// Wait for multiple handles using CoWaitForMultipleObjects
	public static void WaitForHandles( IntPtr[] handles )
	{
		uint index;
		try
		{

			// NOTE: according to MS documentation at
			// https://github.com/MicrosoftDocs/windows-dev-docs/blob/docs/hub/apps/windows-app-sdk/applifecycle/applifecycle-instancing.md
			// this should work... but it doesn't it throws an error with a memory violation.
			// at least it does inside Visual Studio when run in debug, so could be VS's fault

			int result = CoWaitForMultipleObjects( 0 ,  // Flags (0 for default behavior)
															  ( uint )0xFFFFFFFF ,  // Timeout in milliseconds
															  ( uint )handles.Length ,
															  handles[ 0 ] ,
															  out index );

			if ( result == 0 )
			{
				Console.WriteLine( $"Handle at index {index} signaled." );
			}
			else
			{
				Console.WriteLine( "Wait failed or timed out." );
			}
		}
		catch ( Exception ex )
		{
			// we crashed, so do nothing
		}
	}
}

	private bool DecideRedirection( string key )
	{
		bool isRedirect = false;

		// Find out what kind of activation this is.
		AppActivationArguments args = AppInstance.GetCurrent().GetActivatedEventArgs();
		ExtendedActivationKind kind = args.Kind;
		if ( kind == ExtendedActivationKind.Launch )
		{
			try
			{
				AppInstance keyInstance = AppInstance.FindOrRegisterForKey( key );

				// If we successfully registered the file name, we must be the
				// only instance running that was activated for this file.
				if ( keyInstance.IsCurrent )
				{
					// Hook up the Activated event, to allow for this instance of the app
					// getting reactivated as a result of multi-instance redirection.
					keyInstance.Activated += OnKeyInstanceActivated;
				}
				else
				{
					isRedirect = true;

					//Utility.HandleWaiterInterop waiter = new HandleWaiterInterop();

					// Ensure we don't block the STA, by doing the redirect operation
					// in another thread, and using an event to signal when it has completed.
					var redirectSemphore = new Semaphore( 0 , 1 );
					Task.Run( () =>
					{
						keyInstance.RedirectActivationToAsync( args ).AsTask().Wait();
						redirectSemphore.Release();
					} );
					redirectSemphore.WaitOne();

				}
			}
			catch ( Exception ex )
			{
				Debug.WriteLine( $"Error getting instance information: {ex.Message}" );
			}
		}

		return isRedirect;
	}