// 獲取本地藍牙適配器mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

// 判斷手機是否支持藍牙 if (mBluetoothAdapter == null) {  Toast.makeText(this, "設備不支持藍牙", Toast.LENGTH_SHORT).show();  finish(); } // 判斷是否打開藍牙 if (!mBluetoothAdapter.isEnabled()) {  // 彈出對話框提示用戶是后打開  Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);  startActivityForResult(intent, 1);  // 不做提示，強行打開  // mBluetoothAdapter.enable(); }else {  // 不做提示，強行打開   mBluetoothAdapter.enable(); }

// 獲取已經配對的設備 Set<BluetoothDevice> pairedDevices = mBluetoothAdapter   .getBondedDevices(); // 判斷是否有配對過的設備 if (pairedDevices.size() > 0) {  for (BluetoothDevice device : pairedDevices) {   // 遍歷   mDevicesList.add(device.getAddress());   tvDevices.append(device.getName() + ":" + device.getAddress() + "/n");  } }

// 找到設備的廣播IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);// 注冊廣播registerReceiver(receiver, filter);// 搜索完成的廣播filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);// 注冊廣播registerReceiver(receiver, filter);

 private void scanBluth() {// 設置進度條setProgressBarIndeterminateVisibility(true);setTitle("正在搜索...");// 判斷是否在搜索,如果在搜索，就取消搜索if (mBluetoothAdapter.isDiscovering()) {mBluetoothAdapter.cancelDiscovery();}// 開始搜索mBluetoothAdapter.startDiscovery();}

 private final BroadcastReceiver receiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) {  // 收到的廣播類型  String action = intent.getAction();  // 發現設備的廣播  if (BluetoothDevice.ACTION_FOUND.equals(action)) {   // 從intent中獲取設備   BluetoothDevice device = intent     .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);   String aa = tvDevices.getText().toString() + "";   if (aa.contains(device.getAddress())) {    return;   } else {    // 判斷是否配對過    if (device.getBondState() != BluetoothDevice.BOND_BONDED) {     // 添加到列表     short rssi = intent.getExtras().getShort(       BluetoothDevice.EXTRA_RSSI);     int iRssi = abs(rssi); // 將藍牙信號強度換算為距離     double power = (iRssi - 59) / 25.0;     String mm = new Formatter().format("%.2f", pow(10, power)).toString();     tvDevices.append(device.getName() + ":"       + device.getAddress() + " ：" + mm + "m" + "/n");    }else {    }   }   // 搜索完成  } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED    .equals(action)) {   // 關閉進度條   setProgressBarIndeterminateVisibility(true);   setTitle("搜索完成！");   mBLHandler.sendEmptyMessageDelayed(1, 1000);  } }};

// 用于循環掃描藍牙的hangdlerHandler mBLHandler = new Handler() { @Override public void handleMessage(Message msg) {  super.handleMessage(msg);  switch (msg.what) {   case 1:    scanBluth();    break;   default:    break;  } }};

//所有手機需要的權限，藍牙功能才能正常使用 <uses-permission android:name="android.permission.BLUETOOTH" /><uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />//部分手機（如小米等）需要將下面兩個權限添加進去，藍牙功能才能正常使用<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /><uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />