Ionic Capacitor应用无法检测BLE设备（仅Android 13出现）

我开发了一个基于Ionic Capacitor的应用，使用@capacitor-community/bluetooth-le插件。操作系统能检测到Beacon，但应用无法检测到，这个问题只出现在Android 13设备上。

环境信息 #

ionic info 输出 #

Ionic:

   Ionic CLI                     : 7.1.5 (/usr/local/lib/node_modules/@ionic/cli)
   Ionic Framework               : @ionic/angular 7.5.5
   @angular-devkit/build-angular : 17.0.1
   @angular-devkit/schematics    : 17.0.1
   @angular/cli                  : 17.0.1
   @ionic/angular-toolkit        : 9.0.0

Capacitor:

   Capacitor CLI      : 5.5.1
   @capacitor/android : 5.5.1
   @capacitor/core    : 5.5.1
   @capacitor/ios     : not installed

Utility:

   cordova-res (update available: 0.15.4) : 0.15.3
   native-run (update available: 2.0.0)   : 1.7.4

System:

   NodeJS : v20.9.0 (/usr/local/bin/node)
   npm    : 10.1.0

Java版本 #

java version "1.8.0_361"
Java(TM) SE Runtime Environment (build 1.8.0_361-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.361-b09, mixed mode)

代码片段（app.component.ts） #

import { Component, OnInit } from '@angular/core';
import { Capacitor } from '@capacitor/core';
import { BleClient } from '@capacitor-community/bluetooth-le';

@Component({
  selector: 'app-root',
  templateUrl: 'app.component.html',
  styleUrls: ['app.component.scss'],
})
export class AppComponent implements OnInit {
  isLocationEnabled: any;
  isBLEEnabled: any;
  deviceId: any;
  ble: boolean = false;
  devices: any[] = [];
  response: any;

  constructor(
  ) {}

  async ngOnInit() {
  try {
    if (Capacitor.getPlatform() == 'android'){
      this.isLocationEnabled = await BleClient.isLocationEnabled();
    } else {
      this.isLocationEnabled = true;
    }
    await BleClient.initialize();
    this.isBLEEnabled = await BleClient.isEnabled();
    if (this.isBLEEnabled && this.isLocationEnabled) {
      this.ble = true;
      this.startScanning();
    }
    } catch (error) {
      console.error(error)
    }
  }

  startScanning() {
      BleClient.requestLEScan({ allowDuplicates: false }, (res1) => {
        console.log('Device found', res1)  
      });
  }
}

解决方案 #

1. 补充Android 13专属权限 #

Android 13对BLE扫描新增了独立权限控制，需在AndroidManifest.xml中添加：

<!-- Android 13+ 必需的BLE扫描权限 -->
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
<!-- Beacon扫描依赖定位，需添加精细定位权限 -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- 若需后台扫描，需补充后台定位权限 -->
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />

2. 动态申请权限 #

Android 13要求BLUETOOTH_SCAN和定位权限必须在运行时动态申请，修改ngOnInit逻辑：

import { PermissionState, Permissions } from '@capacitor/core';

async ngOnInit() {
  try {
    if (Capacitor.getPlatform() === 'android') {
      // 申请BLE扫描权限
      const scanPerm = await Permissions.request({
        permissions: ['android.permission.BLUETOOTH_SCAN'],
      });
      // 申请精细定位权限
      const locPerm = await Permissions.request({
        permissions: ['android.permission.ACCESS_FINE_LOCATION'],
      });

      // 检查权限是否通过
      if (scanPerm['android.permission.BLUETOOTH_SCAN'] !== PermissionState.Granted ||
          locPerm['android.permission.ACCESS_FINE_LOCATION'] !== PermissionState.Granted) {
        console.error('缺少必要权限，无法扫描BLE设备');
        return;
      }

      this.isLocationEnabled = await BleClient.isLocationEnabled();
    } else {
      this.isLocationEnabled = true;
    }

    await BleClient.initialize();
    this.isBLEEnabled = await BleClient.isEnabled();
    if (this.isBLEEnabled && this.isLocationEnabled) {
      this.ble = true;
      this.startScanning();
    }
  } catch (error) {
    console.error(error);
  }
}

3. 优化扫描配置 #

Android 13对无过滤的BLE扫描限制更严格，建议添加Beacon的服务UUID过滤，减少扫描负载：

startScanning() {
  BleClient.requestLEScan(
    {
      allowDuplicates: false,
      services: ['YOUR_BEACON_UUID'] // 替换为你的Beacon专属UUID
    },
    (res1) => {
      console.log('Device found', res1);
    }
  );
}

4. 检查后台扫描限制 #

若应用需要在后台持续扫描Beacon，除了添加ACCESS_BACKGROUND_LOCATION权限，还需确保应用处于前台服务状态，避免被系统限制扫描频率。

内容的提问来源于stack exchange，提问作者Alvaro Cortizo