map display empty although i assign values to lat and lng ?

I work on angular 7

I assign values of lng and lat on function and map display empty why and how to solve problem

const coordinates = new google.maps.LatLng(lat ,lng);

map not display

if i make map as following it work

//const coordinates = new google.maps.LatLng(40.73061, -73.935242);

the below not working although lat and lng have initial values

const coordinates = new google.maps.LatLng(lat ,lng);

why and how to solve problem

import { Component, OnInit } from '@angular/core';
import { AfterViewInit, ViewChild, ElementRef } from '@angular/core';
import { PartDetailsService } from 'src/app/service/part-details.service';
import { Location } from '@angular/common';
import { ActivatedRoute, Router , ParamMap } from '@angular/router';
import { FmdService } from './../../service/fmd.service';
import { CompanyService } from './../../service/company.service';
@Component({
selector: 'app-managelocations',
templateUrl: './managelocations.component.html',
styleUrls: ['./managelocations.component.css']
})
export class ManagelocationsComponent implements OnInit,AfterViewInit {
PartId: number;
LocationId:number;
lat2:number;
lng2:number;
public data: any;
public dataLocation: any;
title = 'angular-gmap';
@ViewChild('mapContainer') gmap: ElementRef;
map: google.maps.Map;
constructor(public partDetailsService: PartDetailsService
, public companyService: CompanyService
, private location: Location
, public router: Router
, private route: ActivatedRoute
, private fmdService: FmdService) {
//this.route.queryParams.subscribe(params => {
//this.PartId = params['PartId'];
//});
}
ngOnInit() {
}
ngAfterViewInit() {
this.mapInitializer();
}
mapInitializer() {
//============================assign latitude and longtude=======
this.route.queryParams.subscribe(params => {
this.PartId=this.partDetailsService.currentData.PID;
console.log("ManageLocations" + this.PartId);
if (this.PartId != undefined || this.PartId != null)
{
this.data=this.partDetailsService.currentData;
console.log(this.partDetailsService.currentData);
this.LocationId= this.data.Locations[0]['Loc'];
console.log(this.LocationId.toString());
//get location id from parts data
//get locations====================
this.partDetailsService.getLocationData(this.LocationId).subscribe(res => {
this.dataLocation = res['_source']['GPS1'];
var loc = this.dataLocation.split(',');
this.lat2 = loc[0].trim();
this.lng2 = loc[1].trim();
console.log("Lat is " + this.lat2 )
console.log("Lng is " + this.lng2 )
}
);
//=================================
}
});
console.log("Lat2 is " + this.lat2 )
console.log("Lng2 is " + this.lng2 )
//=========================
var lat=this.lat2;
var lng=this.lng2;
console.log("Lat is " + lat )
console.log("Lng is " + lng )
const coordinates = new google.maps.LatLng(lat ,lng);
//const coordinates = new google.maps.LatLng(40.73061, -73.935242);
const mapOptions: google.maps.MapOptions = {
center: coordinates,
zoom: 8
};
const marker = new google.maps.Marker({
position: coordinates,
title: 'Hello World!'
});
const map = new google.maps.Map(this.gmap.nativeElement, mapOptions);
marker.setMap(map);
}
}

1 Reply

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Laxmidhar Sahoo6y ago
hey your code is currect .Just change the order and add map to marker object loike below
const map = new google.maps.Map(this.gmap.nativeElement, mapOptions);
const marker = new google.maps.Marker({
      map: map,
      position: coordinates,
      title: 'Hello World!'
    });


    marker.setMap(map);