如何修复Angular中的“找不到函数名称”错误

时间:2018-12-31 11:48:26

标签: angular google-maps

我正在使用Angular 6通过Google Maps Direction API实现基于Google Maps的应用程序。我在项目中使用了以下初始代码。但是当ng服务时,它会显示 Cannot find name 'calculateAndDisplayRoute'

我已经尝试过在类上方声明函数名称'calculateAndDisplayRoute',但似乎也不起作用。

这是什么问题?

import { Component, OnInit } from '@angular/core';
declare var google: any;

@Component({
  selector: 'app-home',
  templateUrl: './home.component.html',
  styleUrls: ['../../resources/css/style.min.css', '../../resources/css/bt.min.css']
})

// declare var calculateAndDisplayRoute(directionsService, directionsDisplay) : any;

export class HomeComponent implements OnInit {

    initMap() {
        var directionsService = new google.maps.DirectionsService;
        var directionsDisplay = new google.maps.DirectionsRenderer;
        var map = new google.maps.Map(document.getElementById('map'), {
            zoom: 7,
            center: {lat: 41.85, lng: -87.65}
        });
        directionsDisplay.setMap(map);

        var onChangeHandler = function() {
            calculateAndDisplayRoute(directionsService, directionsDisplay);
        };
        document.getElementById('start').addEventListener('change', onChangeHandler);
        document.getElementById('end').addEventListener('change', onChangeHandler);
    }

    calculateAndDisplayRoute(directionsService, directionsDisplay) {
        directionsService.route({
            origin: (<HTMLInputElement>document.getElementById('start')).value,
            destination: (<HTMLInputElement>document.getElementById('end')).value,
            travelMode: 'DRIVING'
        }, function(response, status) {
            if (status === 'OK') {
                directionsDisplay.setDirections(response);
            } 
            else {
                window.alert('Directions request failed due to ' + status);
            }
        });
    }

    constructor() {

    }

    ngOnInit() {
        this.initMap();
    }

}

1 个答案:

答案 0 :(得分:1)

您应该在打字稿中使用箭头功能

var onChangeHandler = () => {
            calculateAndDisplayRoute(directionsService, directionsDisplay);
        };