如何在 Ionic 4 中检查蓝牙状态

Question

我是 Ionic 4 的新手，我正在尝试使用 @ionic-native/diagnostic 检查蓝牙状态，这是我的代码 app.module.ts

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    CheckRegInfo
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    TranslateModule.forRoot({
      loader: {
        provide: TranslateLoader,
        useFactory: (createTranslateLoader),
        deps: [HttpClient]
      }
    }),
    IonicModule.forRoot(MyApp)
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    CheckRegInfo
  ],
  providers: [
    StatusBar,
    SplashScreen,
    Diagnostic,
    {provide: ErrorHandler, useClass: IonicErrorHandler}
  ]
})
export class AppModule {}

校验函数：

import { Component } from '@angular/core';
import {AlertController, NavController} from 'ionic-angular';
import {Diagnostic} from "@ionic-native/diagnostic/ngx";

@Component({
  selector: 'page-check',
  templateUrl: 'check.html'
})
export class CheckRegInfo {
  logowhitesrc:string = "assets/imgs/logowhite.png";
  constructor(public navCtrl: NavController, private alertController:AlertController, private diagnostic: Diagnostic) {

  }
  checkBluetoothState(){
    let titleStr: string;
    this.diagnostic.getBluetoothState()
      .then((state) => {
        if (state == this.diagnostic.bluetoothState.POWERED_ON){
          titleStr = "Okay"
        } else {
          titleStr = "Not Okay"
        }
      }).catch(e => console.error(e));
    let addAlert = this.alertController.create({
      title:"Bluetooth state",
      message:titleStr
    });
    addAlert.present();
  }

}

但是当我在设备上尝试这个时，没有任何反应？我尝试使用 ionic serve -> 它会出现错误 Object(...) is not a function

Answer 1

尝试以下操作：

declare let cordova: any;

@Component({
 selector: 'page-check',
 templateUrl: 'check.html'
})

export class CheckRegInfo {
  logowhitesrc : string = "assets/imgs/logowhite.png";

  constructor(public navCtrl          : NavController, 
              private alertController : AlertController, 
              private diagnostic      : Diagnostic) {}

checkBluetoothState(){
   let titleStr: string;
   cordova.plugins.diagnostic.getBluetoothState().then((state) => {
    if (state == cordova.plugins.diagnostic.bluetoothState.POWERED_ON){
      titleStr = "Okay";
      showAlert(titleStr);
    } else {
      titleStr = "Not Okay";
      showAlert(titleStr);
    }
  }).catch(e => console.error(e));
}

showAlert(title){
  let addAlert = this.alertController.create({
    title  :"Bluetooth state",
    message:titleStr
 });
 addAlert.present();
}

根据文档，您需要使用 cordova.plugins.diagnostic:

来调用它

The core plugin module is exposed via the global cordova.plugins.diagnostic object and it aliases all functions and properties of the other optional modules.

另外，由于then()用于异步操作，所以需要调用.then()内部的方法showAlert(titleStr)。

如何在 Ionic 4 中检查蓝牙状态

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