Windows Moible, Wince 使用.NET Compact Framework的进行蓝牙(Bluetooth)广播程序的开发.doc

Windows Moible, Wince 使用.NET Compact Framework的进行蓝牙(Bluetooth)广播程序的开发简述本文讲述如何使用32feet.NET实现Bluetooth的广播程序，同时演示了Broadcom stack在Windows Mobilie下的实现。背景在.NET Compact Framework下的Bluetooth开发 之 32feet.NET的反馈中camper9999同学希望实现蓝牙广播的功能，本文就是一个基于32feet.NET蓝牙广播的实现。sammylp的提出代码挂死问题，其实是使用过程的不恰当造成的，本文演示如何使用线程防止UI线程的挂起，程序的假死。另外一个同学(不好意思忘记哪位了)问32feet.NET是否支持Broadcom stack，所以本文的实现运行于安装Broadcom stack的windows mobile中。感谢各位的反馈，现在尽量在一篇文章中回答。关于Bluetooth开发的也可以参考以下其他文章：.NET Compact Framework下的Bluetooth开发 之 Windows Embedded Source Tools for Bluetooth.NET Compact Framework下的Bluetooth开发 之 32feet.NET.NET Compact Framework下的Bluetooth开发 之 Bluetooth Virtual Serial Port.NET Compact Framework下的Bluetooth设备的配对30 Days of .NET Windows Mobile Applications - Day 02: Bluetooth Manager(蓝牙管理器)什么是广播所谓广播就是消息发送方向公众(public)发送信息的过程，广播有一个主要的特点是消息发送方不需要知道消息接收方的存在。现实生活中广播的例子如收音机广播，GPS卫星广播，以太网同网段数据包的广播等等。可是所谓蓝牙广播其实不算严格下的广播，因为蓝牙通信过程中有发现，配对，甚至验证过程，所以通信双方是需要握手的，没办法实现严格意义上的广播。本文例子实现了一个通过注册订阅方式的组播过程(MultiCast)。实现服务端服务端负责监听和注册服务，同时把消息发送到已经注册的设备去。在例子中服务端使用PC实现，其实可以使用Windows Mobilie作为服务端，32库基本兼容PC和CE。成员定义private BluetoothListener listener;private bool listening = true;private List clientList = new List();private System.Threading.Thread listenThread;private System.Threading.Thread broadcastThread;listener负责监听服务，clientList 存放已经注册的设备，listenThread负责监听的线程，broadcastThread负责广播的线程。启动服务BluetoothRadio radio = BluetoothRadio.PrimaryRadio;if (radio = null) WriteMessage(No radio hardware or unsupported software stack); return;/ Enable discoverable moderadio.Mode = RadioMode.Discoverable;WriteMessage(Radio Name: + radio.Name);WriteMessage(Radio Address: + radio.LocalAddress);WriteMessage(Radio Mode now: + radio.Mode.ToString();listener = new BluetoothListener(BluetoothService.SerialPort);listener.Start();listening = true;listenThread = new System.Threading.Thread(ListenLoop);broadcastThread = new System.Threading.Thread(BroadcastLoop);listenThread.Start();broadcastThread.Start();WriteMessage(Service started!);启动服务的流程是：1.检查蓝牙设备是否准备好。2.设置蓝牙设备为可发现。3.启动蓝牙监听，这里配置的服务类型为串口服务，在客户端也需要配置串口服务类型才能进行通信。4.启动监听线程，这样不会挂死主线程(Main Thread)。5.启动广播线程。监听线程private void ListenLoop() byte buffer = new byte4; string dataToSend = Thanks for subscription; byte dataBuffer = System.Text.ASCIIEncoding.ASCII.GetBytes(dataToSend); while (listening) try BluetoothClient client = listener.AcceptBluetoothClient(); WriteMessage(Get a subscription from + client.RemoteMachineName); clientList.Add(client); System.IO.Stream ns = client.GetStream(); ns.Write(dataBuffer, 0, dataBuffer.Length); catch break; listener.Stop();监听线程负责处理监听订阅请求，并把订阅的设备增加到订阅列表中。AcceptBluetoothClient()会挂起改线程，直到有新的设备进行订阅。广播线程private void BroadcastLoop() List tempClientList = new List(); while (listening) System.Threading.Thread.Sleep(5000); string dataToSend = Broadcast Message at + System.DateTime.Now.ToLongTimeString(); byte dataBuffer = System.Text.ASCIIEncoding.ASCII.GetBytes(dataToSend); tempClientList.Clear(); foreach (BluetoothClient client in clientList) try System.IO.Stream ns = client.GetStream(); ns.Write(dataBuffer, 0, dataBuffer.Length); WriteMessage(Sent message to + client.RemoteMachineName); catch /connection is broken. tempClientList.Add(client); continue; /clean up the broken connections. foreach (BluetoothClient client in tempClientList) clientList.Remove(client); 广播线程负责对已经订阅的设备进行消息广播，同时管理已经断开的链接。在实际应用中，这个线程需要根据需求来更改业务流程。关闭服务WriteMessage(Service stop!);listening = false;if (listener != null) listener.Stop();释放监听资源。UI处理由于使用了多线程，不能直接更新UI，所以需要借助delegate和Invoke()函数来更新。public delegate void SafeWinFormsThreadDelegate(string msg);private void WriteMessage(string msg) SafeWinFormsThreadDelegate d = new SafeWinFormsThreadDelegate(UpdateUi); Invoke(d, new object msg );private void UpdateUi(string msg) if (listBoxMsg.Items.Count 100) listBoxMsg.Items.RemoveAt(0); listBoxMsg.SelectedIndex = listBoxMsg.Items.Add(msg);客户端客户端负责发现服务端设备，同时发起订阅请求，然后接收广播消息。客户端使用安装了BroadCom stack的Windows Mobile实现，实际上同时支持MS stack。发现BluetoothRadio radio = BluetoothRadio.PrimaryRadio;if (radio = null) WriteMessage(No radio hardware or unsupported software stack); return;/Broadcom stack doesnt support the functionality to turn on the bluetooth, turn it on manually please/radio.Mode = RadioMode.Connectable;/Scan the nearby deviceslistBoxDevices.Items.Clear();BluetoothDeviceInfo devices = client.DiscoverDevices();listBoxDevices.DataSource = devices;listBoxDevices.DisplayMember = DeviceName;listBoxDevices.ValueMember = DeviceAddress;WriteMessage(Discover successful, please select one device to subscribe.);由于当前版本的32在BroadCom stack下不支持设置蓝牙状态，所以如果设备是BroadCom stack需要屏蔽设置蓝牙状态的语句。把发现到的设备显示到ListBox里面。订阅BluetoothAddress deviceAddress = listBoxDevices.SelectedValue as BluetoothAddress;client.Connect(deviceAddress, BluetoothService.SerialPort);WriteMessage(Connected to + client.RemoteMachineName);stream = client.GetStream();receiving = true;System.Threading.Thread t = new System.Threading.Thread(ReceiveLoop);t.Start();根据发现的服务端设备的地址进行连接，然后启动线程接收消息。接收消息private void ReceiveLoop() byte buffer = new byte255; while (receiving) if (stream.CanRead) stream.Read(buffer, 0, 255); string data = System.Text.ASCIIEncoding.ASCII.GetString(buffer, 0, 255); WriteMessage(data); 在线程里接收消息，避免主UI线程挂死。源代码：/procoder/BtBroadcast.rar平台：Visual Studio 2008 + Windows Mobile 5 Packet PC SDKtaob http:/ban