如何使用c# NetworkStream ReadAsync()只抓取stx和etx之间的东西?

我正在尝试构建一个新的应用程序，通过TCP/IP与另一个完成的应用程序通信。这两个应用程序在彼此之间来回传递消息。下面是我的一些服务器代码，这些代码来自我的新应用程序，从完成的应用程序中读取内容:

public class AsyncService
{
    private IPAddress ipAddress;
    private int port;
    char[] STX = new char[] { '' };
    char[] ETX = new char[] { '' };
    NetworkStream networkStream;
    TcpClient tcpClient;
    private byte[] rawBuffer;
    private static readonly int RAWBUFFERSIZE = 2024;
    public AsyncService(int port)
    {
        this.port = port;
        string hostName = Dns.GetHostName();
        IPHostEntry ipHostInfo = Dns.GetHostEntry(hostName);
        rawBuffer = new byte[RAWBUFFERSIZE];
        this.ipAddress = IPAddress.Any;
        if (this.ipAddress == null)
        {
            throw new Exception("No IPv4 address for server");
        }
    }
    public async void Run()
    {
        TcpListener listener = new TcpListener(this.ipAddress, this.port);
        listener.Start();
        while (true)
        {
            try
            {
                tcpClient = await listener.AcceptTcpClientAsync();
                networkStream = tcpClient.GetStream();
                DoReadAsync(rawBuffer);
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
        }
    }
    private void DoReadAsync(byte[] byteBuffer)
    {
        Task<int> t = networkStream.ReadAsync(byteBuffer, 0, byteBuffer.Length);
        t.ContinueWith((task, bytes) => OnReadCompleted((byte[])bytes, task.Result), byteBuffer, TaskContinuationOptions.OnlyOnRanToCompletion);
    }
    private void OnReadCompleted(byte[] byteBuffer, int length)
    {
        if (length == 0)
        {
            return;
        }
        string message = ASCIIEncoding.ASCII.GetString(byteBuffer);
        //...
        Array.Clear(byteBuffer, 0, byteBuffer.Length);
        DoReadAsync(byteBuffer);
    }

发送的每个消息都以STX字符开头，以ETX字符结尾。问题是，我的新应用程序有时会同时接收多个消息。例如，我可能会收到这样的消息:

[STX] 123456789 [ETX] [STX] 123456789 [ETX]

我想让我的代码，我只读取，直到我击中一个ETX字符。因此，我希望上面的例子是两个消息，但我不知道如何使用ReadAsync()。有人知道我该怎么做吗?