Stream.Flush不是流中的Flushing数据

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using InTheHand.Net.Bluetooth;
using InTheHand.Net.Sockets;
using InTheHand.Net.Ports;
using System.IO;

Guid muuid = new Guid("00001101-0000-1000-8000-00805F9B34FB"); 
private void scan()
        {
            UpdateUI("Starting Scan...");
            BluetoothClient client = new BluetoothClient();

            Devices = client.DiscoverDevicesInRange();
            UpdateUI("Scan Complete");
            foreach (BluetoothDeviceInfo d in Devices)
            {
                items.Add(d.DeviceName);
            }
            UpdateDeviceList();
        }  
private void StartScan()
        {
            lb_BT.DataSource = null;
            lb_BT.Items.Clear();
            items.Clear();
            Thread bluetoothScanThread = new Thread(new ThreadStart(scan));
            bluetoothScanThread.Start();
        }

        BluetoothDeviceInfo[] Devices;
 private void UpdateDeviceList()
        {
            Func<int> del = delegate()
            {
                lb_BT.DataSource = items;
                return 0;
            };
            Invoke(del);
        }
  BluetoothDeviceInfo deviceInfo;
private void ClientConnectThread()
        {
            BluetoothClient client = new BluetoothClient();
            UpdateUI("Attempting connect");
            client.BeginConnect(deviceInfo.DeviceAddress, muuid, this.BluetoothClientConnectCallback, client);
        }
 Stream stream = null;
  public void BluetoothClientConnectCallback(IAsyncResult res)
        {

            {

                BluetoothClient client = (BluetoothClient)res.AsyncState;
                client.EndConnect(res);
                stream = client.GetStream();

                else
                {
                    SetupObj.bInitialize(stream);
                }

                //fpcresp[0] = (byte)stream.ReadByte();

            }
        }

    private void writeCmd(byte[] buffer)
        {
            try
            {
        stream.Flush();
              stream.Write(buffer, 0, buffer.Length);
              retCode = SUCCESS;
            }
            catch (Exception ex)
            {
                retCode = FAILURE;
                Debug.WriteLine("Write IO Exception " + ex.Message);
            }
        } 
    private byte[] ReadCmd()
        {

            if( stream!= null)
            {

                byte[] BytesRead = new byte[100];
                int BytesReadCnt = 0;
                stream.Read(BytesRead, 0, 3);
                return BytesRead; 
            }
            else
            {
                return null;
            }

        }

首先我会调用writeCmd，然后调用ReadCmd。有时会发生什么，我在ReadCmd中获取未读数据。（因为上次writeCmd）所以我使用了stream.Flush（）;在每个writeCmd之前。那么流上的数据也不是法拉盛。