Angular Cli-未找到Dojo模块

我正在使用Argis 4.8 JS api开发角度应用程序。我需要Dojo / On功能。我在编译器中也没有收到错误。但是，当我编译时，出现错误“找不到模块：错误：无法解析'dojo / on'路径”。我不能使用Dojo类。我该怎么办？

我的完整代码

import {Component, OnInit, ViewChild, ElementRef, Input, Output, EventEmitter} from '@angular/core';
import {loadModules} from 'esri-loader';
import esri = __esri;
import on = require('dojo/on');


function executeIdentifyTask(event: Event | undefined) {
  console.log(event);
}

@Component({
  selector: 'app-esri-map',
  templateUrl: './esri-map.component.html',
  styleUrls: ['./esri-map.component.css']
})

export class EsriMapComponent implements OnInit {

  @ViewChild('mapViewNode') private mapViewEl: ElementRef;

  constructor() {
  }

  map: esri.Map;
  mapView: esri.MapView;
  layer: esri.MapImageLayer;
  identifyTask: esri.IdentifyTask;

  async initializeMap() {

    try {
      const [EsriMap, EsriMapView, MapImageLayer, IdentifyTask, IdentifyTaskProperties] = await loadModules([
        'esri/Map',
        'esri/views/MapView',
        'esri/layers/MapImageLayer',
        'esri/tasks/IdentifyTask',
        'esri/tasks/support/IdentifyParameters'
      ]);


      this.map = new EsriMap({
        basemap: 'dark-gray'
      });


      this.mapView = new EsriMapView({
        container: this.mapViewEl.nativeElement,
        center: [27.1428, 38.4237],
        zoom: 15,
        map: this.map
      });

      this.layer = new MapImageLayer(
        {url: 'https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer'});

      this.map.add(this.layer);
      this.mapView.when(function () {
        on(this.mapView , 'click' , executeIdentifyTask);
      });

    } catch (error) {
      console.log('We have an error: ' + error);
    }

  }

  ngOnInit() {
    this.initializeMap();
  }

}