Question

我正在学习ionic 5，并且想要创建一个简单的应用程序，该应用程序显示附近所有支持蓝牙的手机的列表。我的问题是，当我使用BLE插件的调用扫描时，永远不会调用我的回调方法。我在连接的手机（三星9）上进行了测试，还生成了app-debug.apk并在手机上进行了测试。

这是我的项目的详细信息。我正在将Capacitor用于本机应用程序。

SDK：

tab-1.ts

import { Component, NgZone } from '@angular/core';
import { BLE } from '@ionic-native/ble/ngx';
import { AlertController } from '@ionic/angular';

@Component({
  selector: 'app-tab1',
  templateUrl: 'tab1.page.html',
  styleUrls: ['tab1.page.scss']
})
export class Tab1Page {
text = 'hello';
devices: any[] = [];
constructor(private ble: BLE,
            private ngZone: NgZone,
            public alertController: AlertController) { }
 scan() {
  this.text = 'Loading...';
  console.log('going to this.scan.....');
  this.devices = [];
  this.showAlert('starting scan.....');


  this.ble.scan([], 60).subscribe(devices1=>{
    this.showDeviceList(devices1);
    this.text = devices1;
    this.showAlert('scan finished success');
  },error=> this.showAlert('scan fini with error'), 
  ()=>this.showAlert('scan void finish'));
}

async showDeviceList(devices) {
  const alert = await this.alertController.create({
    header: 'Alert',
    subHeader: 'Subtitle',
    message: 'Going to start scan',
    buttons: ['OK']
  });
  await alert.present();
  console.log('devices are ', devices);
  this.ngZone.run(() => {
    this.devices.push(...devices);
    this.text = 'finished';
  });
}

async showAlert(msg){
  const alert = await this.alertController.create({
    header: 'Alert',
    subHeader: 'Subtitle',
    message: msg,
    buttons: ['OK']
  });
  await alert.present();
}
}

离子信息：

Package.json：

{
  "name": "COVID-TRACKING",
  "version": "0.0.1",
  "author": "Ionic Framework",
  "homepage": "https://ionicframework.com/",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/common": "~8.2.14",
    "@angular/core": "~8.2.14",
    "@angular/forms": "~8.2.14",
    "@angular/platform-browser": "~8.2.14",
    "@angular/platform-browser-dynamic": "~8.2.14",
    "@angular/router": "~8.2.14",
    "@capacitor/android": "^2.0.1",
    "@capacitor/core": "2.0.1",
    "@ionic-native/ble": "^5.23.0",
    "@ionic-native/core": "^5.0.7",
    "@ionic-native/splash-screen": "^5.0.0",
    "@ionic-native/status-bar": "^5.0.0",
    "@ionic/angular": "^5.0.0",
    "cordova-plugin-ble-central": "^1.2.4",
    "core-js": "^2.5.4",
    "rxjs": "~6.5.1",
    "tslib": "^1.9.0",
    "zone.js": "~0.9.1"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.803.20",
    "@angular/cli": "~8.3.23",
    "@angular/compiler": "~8.2.14",
    "@angular/compiler-cli": "~8.2.14",
    "@angular/language-service": "~8.2.14",
    "@capacitor/cli": "2.0.1",
    "@ionic/angular-toolkit": "^2.1.1",
    "@types/jasmine": "~3.3.8",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "~8.9.4",
    "codelyzer": "^5.0.0",
    "jasmine-core": "~3.4.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~4.1.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "~2.0.1",
    "karma-jasmine": "~2.0.1",
    "karma-jasmine-html-reporter": "^1.4.0",
    "protractor": "~5.4.0",
    "ts-node": "~7.0.0",
    "tslint": "~5.15.0",
    "typescript": "~3.4.3"
  },
  "description": "An Ionic project"
}

安装插件的命令：

npm install cordova-plugin-ble-central
npm install @ionic-native/ble
ionic cap sync

Answer 1

自android api 29起，使用ACCESS_FINE_LOCATION权限代替ACCESS_COARSE_LOCATION。 cordova-plugin-ble-central的制造商尚未接受可解决此问题的请求请求。

我在叉子上做了必要的更改，并且现在在android 10上运行良好，而没有为应用程序添加背景位置的麻烦。

也许您可以通过删除旧版本来使用它：

ionic cordova plugin rm cordova-plugin-ble-central

并添加我的叉子：

ionic cordova plugin add git+https://github.com/dslima90/cordova-plugin-ble-central.git

Answer 2

问题仅在于android10。您需要android 10中的backgound位置权限才能使蓝牙工作。您需要向AndroidManifest.xml添加后台位置权限，并且即使您不打算使用Background Geolocation插件，也需要将其添加到您的应用中。在您的app.component中执行以下操作

const config: BackgroundGeolocationConfig = {
    desiredAccuracy: 10,
    stationaryRadius: 20,
    distanceFilter: 30,
    debug: true, //  enable this hear sounds for background-geolocation life-cycle.
    stopOnTerminate: false, // enable this to clear background location settings when the app terminates
  };

  this.bgLoc.stop();

完成上述操作后，这将自动请求背景位置权限，并允许蓝牙在android 10上运行。另外，请确保将“粗略位置”权限添加到androidmanifest.xml

Answer 3

尝试了电容器并发现很多问题需要太多时间所以我决定切换回科尔多瓦而不是电容器

IONIC电容器BLE插件扫描不起作用

3 个答案: