在Ionic 2中实现地理位置跟踪的错误

Question

我正在尝试在我的新项目中实现地理定位。我已经安装了以下插件并在app.module.ts中添加了它们

ionic cordova plugin add cordova-plugin-mauron85-background-geolocation npm install --save @ionic-native/background-geolocation

我正在跟踪本教程，但在home.ts中出现了错误。下面是我的home.ts代码。

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { BackgroundGeolocation, BackgroundGeolocationConfig, BackgroundGeolocationResponse } from '@ionic-native/background-geolocation';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(private backgroundGeolocation: BackgroundGeolocation,public navCtrl: NavController) {

  }

  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.backgroundGeolocation.configure(config)
.subscribe((location: BackgroundGeolocationResponse) => {

console.log(location);

// IMPORTANT:  You must execute the finish method here to inform the native plugin that you're finished,
// and the background-task may be completed.  You must do this regardless if your HTTP request is successful or not.
// IF YOU DON'T, ios will CRASH YOUR APP for spending too much time in the background.
//this.backgroundGeolocation.finish(); // FOR IOS ONLY

});

// start recording location
this.backgroundGeolocation.start();

// If you wish to turn OFF background-tracking, call the #stop method.
this.backgroundGeolocation.stop();

}

错误出现在这一行：this.backgroundGeolocation.configure(config)。在this上有这样的说法；

意想不到的记号。需要构造函数、方法、访问器或属性。

在配置上，它说：

ts找不到名称“config”

Answer 1

正如@SurajRao在他的评论中指出的那样，您需要将代码移动到类构造函数中或将其包装在方法中。

下面是放置在构造函数中的代码的组件：

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { BackgroundGeolocation, BackgroundGeolocationConfig, BackgroundGeolocationResponse } from '@ionic-native/background-geolocation';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(private backgroundGeolocation: BackgroundGeolocation,public navCtrl: NavController) {
    const config: BackgroundGeolocationConfig = {
      desiredAccuracy: 10,
      stationaryRadius: 20,
      distanceFilter: 30,
      debug: true,
      stopOnTerminate: false,
    };
    this.backgroundGeolocation.configure(config)
    .subscribe((location: BackgroundGeolocationResponse) => {
      console.log(location);
    });
    this.backgroundGeolocation.start();
    this.backgroundGeolocation.stop();
  }

}

阅读更多关于MDN上的JavaScript类的信息。