Unhandled Exception under Xamarin iOS

I'm using ssh.net in a Xamarin iOS application. When connecting to a sftp server with the iOS 's wifi turn off. I got this exception:
Unhandled Exception:
System.ObjectDisposedException: Safe handle has been closed occurred.
I debug the source code and found out that's because under Xamarin iOS
socket.ConnectAsync(args) return false when wifi is turned off.
SocketAbstraction.cs line 63 if (socket.ConnectAsync(args))
Then it run line 83 connectCompleted.Dispose();
At last function ConnectCompleted was called , where the exception occurred.

If I moved line 83 connectCompleted.Dispose() into below if statement like this:

       if (args.SocketError != SocketError.Success)
        {
            var socketError = (int) args.SocketError;

            // dispose Socket
            socket.Dispose();
            // dispose SocketAsyncEventArgs
            args.Dispose();

            // dispose ManualResetEvent
            connectCompleted.Dispose();

            throw new SocketException(socketError);
        }

then this bug is fixed.

Bắt đầu trong SocketAbstraction.cs quanh dòng 63, nơi socket.ConnectAsync(args) được xử lý, và dòng 83, nơi connectCompleted được giải phóng. Tái hiện kết nối SFTP của Xamarin iOS khi Wi-Fi bị tắt và theo dõi ConnectCompleted. Hoàn thành khi kết nối thất bại tạo ra lỗi socket như mong đợi mà không có ObjectDisposedException.