深入解析：Android BLE 蓝牙扫描完全指南：使用 RxAndroidBle框架

前言

在现代移动应用开发中，蓝牙低功耗（BLE）技术广泛应用于物联网设备、健康监测、智能家居等领域。本文将带你从零开始，完整实现一个 Android BLE 扫描功能。

️ 1. 环境配置

添加依赖

在 app/build.gradle 中添加：

dependencies {
// RxAndroidBle 核心库
implementation "com.polidea.rxandroidble3:rxandroidble:1.17.2"
// RxJava 3
implementation "io.reactivex.rxjava3:rxjava:3.1.6"
implementation "io.reactivex.rxjava3:rxandroid:3.0.2"
// 可选：Lifecycle 用于更好的生命周期管理
implementation "androidx.lifecycle:lifecycle-runtime-ktx:2.6.2"
}

权限配置

在 AndroidManifest.xml 中添加：

<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-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<!-- Android 12+ 需要以下权限 -->
  <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
  <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
  <!-- 如果需要定位功能 -->
    <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />

2. 权限工具类

// PermissionUtils.kt
object PermissionUtils {
/**
* 检查蓝牙权限
*/
@SuppressLint("InlinedApi")
fun checkBluetoothPermissions(context: Context): Boolean {
return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
ContextCompat.checkSelfPermission(context, Manifest.permission.BLUETOOTH_SCAN) == PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission(context, Manifest.permission.BLUETOOTH_CONNECT) == PackageManager.PERMISSION_GRANTED
} else {
ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
}
}
/**
* 获取需要的权限数组
*/
@SuppressLint("InlinedApi")
fun getRequiredPermissions(): Array<String>
  {
  return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
  arrayOf(
  Manifest.permission.BLUETOOTH_SCAN,
  Manifest.permission.BLUETOOTH_CONNECT
  )
  } else {
  arrayOf(Manifest.permission.ACCESS_FINE_LOCATION)
  }
  }
  /**
  * 请求权限
  */
  fun requestBluetoothPermissions(activity: Activity, requestCode: Int) {
  val permissions = getRequiredPermissions()
  ActivityCompat.requestPermissions(activity, permissions, requestCode)
  }
  }

3. 蓝牙扫描工具类

// BleScanner.kt
class BleScanner
(private val context: Context) {
private val rxBleClient: RxBleClient by lazy { RxBleClient.create(context)
}
private var scanDisposable: Disposable? = null
private val scanResultsSubject = PublishSubject.create<ScanResult>
  ()
  private val scannedDevices = mutableMapOf<String, ScanResult>
    ()
    private var isScanning = false
    // 扫描状态回调
    var onScanStateChanged: ((Boolean) -> Unit)? = null
    var onDeviceFound: ((ScanResult) -> Unit)? = null
    var onScanError: ((Throwable) -> Unit)? = null
    /**
    * 开始扫描
    */
    @SuppressLint("MissingPermission")
    fun startScan(scanMode: Int = ScanSettings.SCAN_MODE_LOW_LATENCY) {
    if (!PermissionUtils.checkBluetoothPermissions(context)) {
    onScanError?.invoke(SecurityException("缺少蓝牙扫描权限"))
    return
    }
    stopScan()
    val scanSettings = ScanSettings.Builder()
    .setScanMode(scanMode)
    .setCallbackType(ScanSettings.CALLBACK_TYPE_ALL_MATCHES)
    .build()
    isScanning = true
    onScanStateChanged?.invoke(true)
    scanDisposable = rxBleClient.scanBleDevices(scanSettings)
    .subscribe(
    { scanResult ->
    handleScanResult(scanResult)
    },
    { error ->
    handleScanError(error)
    }
    )
    }
    /**
    * 处理扫描结果
    */
    private fun handleScanResult(scanResult: ScanResult) {
    val macAddress = scanResult.bleDevice.macAddress
    scannedDevices[macAddress] = scanResult
    // 通知监听器
    onDeviceFound?.invoke(scanResult)
    scanResultsSubject.onNext(scanResult)
    }
    /**
    * 处理扫描错误
    */
    private fun handleScanError(error: Throwable) {
    isScanning = false
    onScanStateChanged?.invoke(false)
    onScanError?.invoke(error)
    scanResultsSubject.onError(error)
    }
    /**
    * 停止扫描
    */
    fun stopScan() {
    scanDisposable?.dispose()
    scanDisposable = null
    isScanning = false
    onScanStateChanged?.invoke(false)
    }
    /**
    * 获取扫描结果的Observable
    */
    fun getScanResultsObservable(): Observable<ScanResult>
      {
      return scanResultsSubject
      }
      /**
      * 获取所有扫描到的设备
      */
      fun getAllDevices(): List<ScanResult>
        {
        return scannedDevices.values.toList()
        }
        /**
        * 根据条件过滤设备
        */
        fun filterDevices(
        name: String? = null,
        minRssi: Int? = null,
        maxRssi: Int? = null
        ): List<ScanResult>
          {
          return scannedDevices.values.filter { device ->
          (name == null || device.bleDevice.name?.contains(name, true) == true) &&
          (minRssi == null || device.rssi >= minRssi) &&
          (maxRssi == null || device.rssi <= maxRssi)
          }
          }
          /**
          * 清空扫描结果
          */
          fun clearResults() {
          scannedDevices.clear()
          }
          /**
          * 检查是否正在扫描
          */
          fun isScanning(): Boolean = isScanning
          /**
          * 获取设备数量
          */
          fun getDeviceCount(): Int = scannedDevices.size
          /**
          * 释放资源
          */
          fun release() {
          stopScan()
          scanResultsSubject.onComplete()
          }
          }

4. 设备信息数据类

// BleDeviceInfo.kt
data class BleDeviceInfo
(
val name: String,
val macAddress: String,
val rssi: Int,
val scanRecord: ByteArray?,
val timestamp: Long = System.currentTimeMillis()
) {
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (javaClass != other?.javaClass) return false
other as BleDeviceInfo
return macAddress == other.macAddress
}
override fun hashCode(): Int {
return macAddress.hashCode()
}
}

5. RecyclerView 适配器

// DeviceAdapter.kt
class DeviceAdapter
(
private val onDeviceClick: (BleDeviceInfo) -> Unit
) : RecyclerView.Adapter<DeviceAdapter.DeviceViewHolder>
  () {
  private val devices = mutableListOf<BleDeviceInfo>
    ()
    inner class DeviceViewHolder
    (itemView: View) : RecyclerView.ViewHolder(itemView) {
    private val txtName: TextView = itemView.findViewById(R.id.txtDeviceName)
    private val txtMac: TextView = itemView.findViewById(R.id.txtDeviceMac)
    private val txtRssi: TextView = itemView.findViewById(R.id.txtDeviceRssi)
    fun bind(device: BleDeviceInfo) {
    txtName.text = device.name
    txtMac.text = device.macAddress
    txtRssi.text = "信号: ${device.rssi
    }dBm"
    itemView.setOnClickListener {
    onDeviceClick(device)
    }
    }
    }
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): DeviceViewHolder {
    val view = LayoutInflater.from(parent.context)
    .inflate(R.layout.item_device, parent, false)
    return DeviceViewHolder(view)
    }
    override fun onBindViewHolder(holder: DeviceViewHolder, position: Int) {
    holder.bind(devices[position])
    }
    override fun getItemCount(): Int = devices.size
    fun addOrUpdateDevice(device: BleDeviceInfo) {
    val existingIndex = devices.indexOfFirst { it.macAddress == device.macAddress
    }
    if (existingIndex != -1) {
    devices[existingIndex] = device
    notifyItemChanged(existingIndex)
    } else {
    devices.add(device)
    notifyItemInserted(devices.size - 1)
    }
    }
    fun clear() {
    devices.clear()
    notifyDataSetChanged()
    }
    fun getDevices(): List<BleDeviceInfo>
      = devices.toList()
      }

6. Activity/Fragment 实现

// MainActivity.kt
class MainActivity :
AppCompatActivity() {
companion object {
private const val REQUEST_BLE_PERMISSIONS = 1001
}
private lateinit var bleScanner: BleScanner
private lateinit var deviceAdapter: DeviceAdapter
private var resultsDisposable: Disposable? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
initViews()
initBleScanner()
checkPermissions()
}
private fun initViews() {
deviceAdapter = DeviceAdapter { device ->
onDeviceSelected(device)
}
recyclerViewDevices.apply {
adapter = deviceAdapter
layoutManager = LinearLayoutManager(this@MainActivity)
addItemDecoration(DividerItemDecoration(this@MainActivity, DividerItemDecoration.VERTICAL))
}
btnStartScan.setOnClickListener {
startScanning()
}
btnStopScan.setOnClickListener {
stopScanning()
}
btnClear.setOnClickListener {
clearResults()
}
}
private fun initBleScanner() {
bleScanner = BleScanner(this)
bleScanner.onScanStateChanged = { isScanning ->
updateScanUI(isScanning)
}
bleScanner.onDeviceFound = { scanResult ->
val deviceInfo = convertToDeviceInfo(scanResult)
runOnUiThread {
deviceAdapter.addOrUpdateDevice(deviceInfo)
updateDeviceCount()
}
}
bleScanner.onScanError = { error ->
runOnUiThread {
showError("扫描错误: ${error.message
}")
}
}
}
private fun convertToDeviceInfo(scanResult: ScanResult): BleDeviceInfo {
return BleDeviceInfo(
name = scanResult.bleDevice.name ?: "未知设备",
macAddress = scanResult.bleDevice.macAddress,
rssi = scanResult.rssi,
scanRecord = scanResult.scanRecord?.bytes
)
}
private fun checkPermissions() {
if (!PermissionUtils.checkBluetoothPermissions(this)) {
PermissionUtils.requestBluetoothPermissions(this, REQUEST_BLE_PERMISSIONS)
}
}
@SuppressLint("MissingPermission")
private fun startScanning() {
if (!PermissionUtils.checkBluetoothPermissions(this)) {
PermissionUtils.requestBluetoothPermissions(this, REQUEST_BLE_PERMISSIONS)
return
}
try {
bleScanner.startScan()
observeScanResults()
} catch (e: Exception) {
showError("启动扫描失败: ${e.message
}")
}
}
private fun observeScanResults() {
resultsDisposable = bleScanner.getScanResultsObservable()
.observeOn(AndroidSchedulers.mainThread())
.subscribe({ scanResult ->
val deviceInfo = convertToDeviceInfo(scanResult)
deviceAdapter.addOrUpdateDevice(deviceInfo)
updateDeviceCount()
}, { error ->
showError("扫描错误: ${error.message
}")
})
}
private fun stopScanning() {
bleScanner.stopScan()
resultsDisposable?.dispose()
}
private fun clearResults() {
bleScanner.clearResults()
deviceAdapter.clear()
updateDeviceCount()
}
private fun onDeviceSelected(device: BleDeviceInfo) {
AlertDialog.Builder(this)
.setTitle("选择设备")
.setMessage("设备: ${device.name
}\nMAC: ${device.macAddress
}\n信号强度: ${device.rssi
}dBm")
.setPositiveButton("连接") { _, _ ->
connectToDevice(device.macAddress)
}
.setNegativeButton("取消", null)
.show()
}
private fun connectToDevice(macAddress: String) {
// 这里实现设备连接逻辑
Toast.makeText(this, "连接设备: $macAddress", Toast.LENGTH_SHORT).show()
}
private fun updateScanUI(isScanning: Boolean) {
runOnUiThread {
btnStartScan.isEnabled = !isScanning
btnStopScan.isEnabled = isScanning
progressBar.visibility = if (isScanning) View.VISIBLE else View.GONE
txtStatus.text = if (isScanning) "扫描中..." else "扫描已停止"
}
}
private fun updateDeviceCount() {
txtDeviceCount.text = "设备数量: ${deviceAdapter.itemCount
}"
}
private fun showError(message: String) {
Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
updateScanUI(false)
}
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<
out String>
,
grantResults: IntArray
) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if (requestCode == REQUEST_BLE_PERMISSIONS) {
if (grantResults.all { it == PackageManager.PERMISSION_GRANTED
}) {
startScanning()
} else {
showError("需要蓝牙权限才能扫描")
}
}
}
override fun onDestroy() {
super.onDestroy()
bleScanner.release()
resultsDisposable?.dispose()
}
}

7. 布局文件

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  android:padding="16dp">
<LinearLayout
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal"
  android:gravity="center_vertical">
<Button
  android:id="@+id/btnStartScan"
  android:layout_width="0dp"
  android:layout_height="wrap_content"
  android:layout_weight="1"
  android:text="开始扫描"
  android:layout_marginEnd="8dp"/>
<Button
  android:id="@+id/btnStopScan"
  android:layout_width="0dp"
  android:layout_height="wrap_content"
  android:layout_weight="1"
  android:text="停止扫描"
  android:layout_marginEnd="8dp"
  android:enabled="false"/>
<Button
  android:id="@+id/btnClear"
  android:layout_width="0dp"
  android:layout_height="wrap_content"
  android:layout_weight="1"
  android:text="清空结果"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_vertical"
android:layout_marginTop="16dp">
<ProgressBar
android:id="@+id/progressBar"
android:layout_width="24dp"
android:layout_height="24dp"
android:visibility="gone"/>
<TextView
android:id="@+id/txtStatus"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="准备扫描"
android:layout_marginStart="8dp"
android:textSize="16sp"/>
<TextView
android:id="@+id/txtDeviceCount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="设备数量: 0"
android:textSize="14sp"/>
</LinearLayout>
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerViewDevices"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_marginTop="16dp"/>
</LinearLayout>

item_device.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="vertical"
  android:padding="16dp">
<TextView
  android:id="@+id/txtDeviceName"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:textSize="18sp"
  android:textStyle="bold"/>
<TextView
  android:id="@+id/txtDeviceMac"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:textSize="14sp"
  android:layout_marginTop="4dp"/>
<TextView
  android:id="@+id/txtDeviceRssi"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:textSize="14sp"
  android:layout_marginTop="4dp"/>
</LinearLayout>

8. 使用技巧和最佳实践

扫描模式选择

// 低功耗模式（省电，但扫描间隔长）
ScanSettings.SCAN_MODE_LOW_POWER
// 平衡模式
ScanSettings.SCAN_MODE_BALANCED
// 低延迟模式（快速响应，但耗电）
ScanSettings.SCAN_MODE_LOW_LATENCY
// 机会主义模式（最低功耗）
ScanSettings.SCAN_MODE_OPPORTUNISTIC

错误处理

// 添加重试机制
fun startScanWithRetry(maxRetries: Int = 3) {
var retryCount = 0
bleScanner.getScanResultsObservable()
.retryWhen { errors ->
errors.flatMap { error ->
if (++retryCount < maxRetries) {
Observable.timer(2, TimeUnit.SECONDS)
} else {
Observable.error(error)
}
}
}
.subscribe(...)
}

生命周期管理

// 在 ViewModel 中管理
class BleViewModel
(application: Application) : AndroidViewModel(application) {
private val bleScanner = BleScanner(application)
// 使用 LiveData 暴露状态
private val _scanState = MutableLiveData<Boolean>
  ()
  val scanState: LiveData<Boolean>
    = _scanState
    init {
    bleScanner.onScanStateChanged = { isScanning ->
    _scanState.postValue(isScanning)
    }
    }
    override fun onCleared() {
    super.onCleared()
    bleScanner.release()
    }
    }

总结

本文完整介绍了如何使用 RxAndroidBle 实现 Android BLE 扫描功能，包括：

1. 环境配置和依赖添加
2. 权限管理和检查
3. 核心扫描功能实现
4. UI 界面和列表展示
5. 错误处理和最佳实践

这个实现提供了完整的蓝牙扫描解决方案，可以直接用于生产环境，也可以根据具体需求进行扩展和定制。

优点：

· 响应式编程，代码简洁
· 完整的错误处理
· 自动设备去重
· 灵活的过滤功能
· 良好的生命周期管理

希望这篇指南对你的博客写作有所帮助！