在使用手機時，藍牙通信給我們帶來很多方便。那么在Android手機中怎樣進行藍牙開發呢？本文以實例的方式講解Android藍牙開發的知識。
1、使用藍牙的響應權限
XML/HTML代碼
<uses-permission android:name="android.permission.BLUETOOTH"/> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
2、配置本機藍牙模塊
在這里首先要了解對藍牙操作一個核心類BluetoothAdapter。
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter(); //直接打開系統的藍牙設置面板 Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(intent, 0x1); //直接打開藍牙 adapter.enable(); //關閉藍牙 adapter.disable(); //打開本機的藍牙發現功能（默認打開120秒，可以將時間最多延長至300秒） Intent discoveryIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);//設置持續時間（最多300秒）
3、搜索藍牙設備
使用BluetoothAdapter的startDiscovery()方法來搜索藍牙設備。
startDiscovery()方法是一個異步方法，調用后會立即返回。該方法會進行對其他藍牙設備的搜索，該過程會持續12秒。該方法調用后，搜索過程實際上是在一個System Service中進行的，所以可以調用cancelDiscovery()方法來停止搜索（該方法可以在未執行discovery請求時調用）。
請求Discovery后，系統開始搜索藍牙設備，在這個過程中，系統會發送以下三個廣播：
ACTION_DISCOVERY_START：開始搜索
ACTION_DISCOVERY_FINISHED：搜索結束
ACTION_FOUND：找到設備，這個Intent中包含兩個extra fields：EXTRA_DEVICE和EXTRA_CLASS，分別包含BluetooDevice和BluetoothClass。
我們可以自己注冊相應的BroadcastReceiver來接收響應的廣播，以便實現某些功能。
// 創建一個接收ACTION_FOUND廣播的BroadcastReceiver private final BroadcastReceiver mReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { String action = intent.getAction(); // 發現設備 if (BluetoothDevice.ACTION_FOUND.equals(action)) { // 從Intent中獲取設備對象 BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); // 將設備名稱和地址放入array adapter，以便在ListView中顯示 mArrayAdapter.add(device.getName() + "/n" + device.getAddress()); } } }; // 注冊BroadcastReceiver IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); registerReceiver(mReceiver, filter); // 不要忘了之后解除綁定 4、藍牙Socket通信
如果打算建議兩個藍牙設備之間的連接，則必須實現服務器端與客戶端的機制。當兩個設備在同一個RFCOMM channel下分別擁有一個連接的BluetoothSocket，這兩個設備才可以說是建立了連接。
服務器設備與客戶端設備獲取BluetoothSocket的途徑是不同的。服務器設備是通過accepted一個incoming connection來獲取的，而客戶端設備則是通過打開一個到服務器的RFCOMM channel來獲取的。
服務器端的實現
通過調用BluetoothAdapter的listenUsingRfcommWithServiceRecord(String, UUID)方法來獲取BluetoothServerSocket（UUID用于客戶端與服務器端之間的配對）。
調用BluetoothServerSocket的accept()方法監聽連接請求，如果收到請求，則返回一個BluetoothSocket實例（此方法為block方法，應置于新線程中）。
如果不想在accept其他的連接，則調用BluetoothServerSocket的close()方法釋放資源（調用該方法后，之前獲得的BluetoothSocket實例并沒有close。但由于RFCOMM一個時刻只允許在一條channel中有一個連接，則一般在accept一個連接后，便close掉BluetoothServerSocket）。
private class AcceptThread extends Thread { private final BluetoothServerSocket mmServerSocket; public AcceptThread() { // Use a temporary object that is later assigned to mmServerSocket, // because mmServerSocket is final BluetoothServerSocket tmp = null; try { // MY_UUID is the app's UUID string, also used by the client code tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID); } catch (IOException e) { } mmServerSocket = tmp; } public void run() { BluetoothSocket socket = null; // Keep listening until exception occurs or a socket is returned while (true) { try { socket = mmServerSocket.accept(); } catch (IOException e) { break; } // If a connection was accepted if (socket != null) { // Do work to manage the connection (in a separate thread) manageConnectedSocket(socket); mmServerSocket.close(); break; } } } /** Will cancel the listening socket, and cause the thread to finish */ public void cancel() { try { mmServerSocket.close(); } catch (IOException e) { } } } 客戶端的實現
通過搜索得到服務器端的BluetoothService。
調用BluetoothService的listenUsingRfcommWithServiceRecord(String, UUID)方法獲取BluetoothSocket（該UUID應該同于服務器端的UUID）。
調用BluetoothSocket的connect()方法（該方法為block方法），如果UUID同服務器端的UUID匹配，并且連接被服務器端accept，則connect()方法返回。
注意：在調用connect()方法之前，應當確定當前沒有搜索設備，否則連接會變得非常慢并且容易失敗。
private class ConnectThread extends Thread { private final BluetoothSocket mmSocket; private final BluetoothDevice mmDevice; public ConnectThread(BluetoothDevice device) { // Use a temporary object that is later assigned to mmSocket, // because mmSocket is final BluetoothSocket tmp = null; mmDevice = device; // Get a BluetoothSocket to connect with the given BluetoothDevice try { // MY_UUID is the app's UUID string, also used by the server code tmp = device.createRfcommSocketToServiceRecord(MY_UUID); } catch (IOException e) { } mmSocket = tmp; } public void run() { // Cancel discovery because it will slow down the connection mBluetoothAdapter.cancelDiscovery(); try { // Connect the device through the socket. This will block // until it succeeds or throws an exception mmSocket.connect(); } catch (IOException connectException) { // Unable to connect; close the socket and get out try { mmSocket.close(); } catch (IOException closeException) { } return; } // Do work to manage the connection (in a separate thread) manageConnectedSocket(mmSocket); } /** Will cancel an in-progress connection, and close the socket */ public void cancel() { try { mmSocket.close(); } catch (IOException e) { } } } 5、連接管理（數據通信）
分別通過BluetoothSocket的getInputStream()和getOutputStream()方法獲取InputStream和OutputStream。
使用read(bytes[])和write(bytes[])方法分別進行讀寫操作。
注意：read(bytes[])方法會一直block，知道從流中讀取到信息，而write(bytes[])方法并不是經常的block（比如在另一設備沒有及時read或者中間緩沖區已滿的情況下，write方法會block）。
private class ConnectedThread extends Thread { private final BluetoothSocket mmSocket; private final InputStream mmInStream; private final OutputStream mmOutStream; public ConnectedThread(BluetoothSocket socket) { mmSocket = socket; InputStream tmpIn = null; OutputStream tmpOut = null; // Get the input and output streams, using temp objects because // member streams are final try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { } mmInStream = tmpIn; mmOutStream = tmpOut; } public void run() { byte[] buffer = new byte[1024]; // buffer store for the stream int bytes; // bytes returned from read() // Keep listening to the InputStream until an exception occurs while (true) { try { // Read from the InputStream bytes = mmInStream.read(buffer); // Send the obtained bytes to the UI Activity mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer) .sendToTarget(); } catch (IOException e) { break; } } } /* Call this from the main Activity to send data to the remote device */ public void write(byte[] bytes) { try { mmOutStream.write(bytes); } catch (IOException e) { } } /* Call this from the main Activity to shutdown the connection */ public void cancel() { try { mmSocket.close(); } catch (IOException e) { } } } 以上就Android 藍牙的開發簡單示例代碼，后續繼續整理相關資料，謝謝大家對本站的支持！
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