在Android中使用BLE(蓝牙低功耗)发送数据涉及多个步骤,包括扫描设备、建立连接、发现服务和特征、写入数据等。以下是一个基本的指南,帮助你在Android应用中实现BLE数据发送。
首先,确保在AndroidManifest.xml
中声明了必要的权限:
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>
对于Android 6.0及以上版本,需要动态请求位置权限:
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
REQUEST_ENABLE_LOCATION);
}
在你的Activity或Fragment中初始化蓝牙适配器:
BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter bluetoothAdapter = bluetoothManager.getAdapter();
if (bluetoothAdapter == null || !bluetoothAdapter.isEnabled()) {
// 提示用户启用蓝牙
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
使用BluetoothLeScanner
扫描附近的BLE设备:
BluetoothLeScanner scanner = bluetoothAdapter.getBluetoothLeScanner();
ScanSettings settings = new ScanSettings.Builder()
.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
.build();
List<ScanFilter> filters = new ArrayList<>();
scanner.startScan(filters, settings, scanCallback);
private ScanCallback scanCallback = new ScanCallback() {
@Override
public void onScanResult(int callbackType, ScanResult result) {
BluetoothDevice device = result.getDevice();
// 处理找到的设备
}
// 其他回调方法...
};
找到目标设备后,进行连接:
BluetoothGatt gatt = device.connectGatt(this, false, gattCallback);
private BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
if (newState == BluetoothProfile.STATE_CONNECTED) {
gatt.discoverServices();
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
// 处理断开连接
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
// 获取服务和特征
}
}
// 其他回调方法...
};
在onServicesDiscovered
中查找需要的服务和特征:
BluetoothGattService service = gatt.getService(YOUR_SERVICE_UUID);
if (service != null) {
BluetoothGattCharacteristic characteristic = service.getCharacteristic(YOUR_CHARACTERISTIC_UUID);
if (characteristic != null) {
// 准备写入数据
}
}
确保特征具有写权限,然后写入数据:
byte[] data = "Hello BLE".getBytes(StandardCharsets.UTF_8);
characteristic.setValue(data);
gatt.writeCharacteristic(characteristic);
在BluetoothGattCallback
中处理写入结果:
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
// 数据发送成功
} else {
// 处理错误
}
}
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