Google Map API v3 example from their site doesn't work without an API key but does with a Key. What am I doing wrong?

问题

Problem: I am trying to use a sample of Google Map API v3 without an API key and it doesn't render. (It does render if I use a key).Anyone know why?

I decided to use this example (https://developers.google.com/maps/documentation/javascript/examples/polyline-simple)

In order to make it work without a key I replaced this script:

<script async defer src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&signed_in=true&callback=initMap"></script>

with this other script

<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>

This is the code:

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Simple Polylines</title>
    <style>
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
      #map {
        height: 100%;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <script>

// This example creates a 2-pixel-wide red polyline showing the path of William
// Kingsford Smith's first trans-Pacific flight between Oakland, CA, and
// Brisbane, Australia.

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 3,
    center: {lat: 0, lng: -180},
    mapTypeId: google.maps.MapTypeId.TERRAIN
  });

  var flightPlanCoordinates = [
    {lat: 37.772, lng: -122.214},
    {lat: 21.291, lng: -157.821},
    {lat: -18.142, lng: 178.431},
    {lat: -27.467, lng: 153.027}
  ];
  var flightPath = new google.maps.Polyline({
    path: flightPlanCoordinates,
    geodesic: true,
    strokeColor: '#FF0000',
    strokeOpacity: 1.0,
    strokeWeight: 2
  });

  flightPath.setMap(map);
}

    </script>
    <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
  </body>
</html>

But it doesn't render. Any idea what am I doing wrong? Thanks!

回答1:

Move the google maps script include into the head. It has to be included before you call it.

Call your initMap function to run the function you set up. The function initMap() has only been defined, but you haven't run it until then.

<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Simple Polylines</title>
    <style>
        html, body {
            height: 100%;
            margin: 0;
            padding: 0;
        }

        #map {
            height: 100%;
        }
    </style>
    <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
</head>
<body>
    <div id="map"></div>
    <script>

// This example creates a 2-pixel-wide red polyline showing the path of William
// Kingsford Smith's first trans-Pacific flight between Oakland, CA, and
// Brisbane, Australia.

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 3,
    center: {lat: 0, lng: -180},
    mapTypeId: google.maps.MapTypeId.TERRAIN
  });

  var flightPlanCoordinates = [
    {lat: 37.772, lng: -122.214},
    {lat: 21.291, lng: -157.821},
    {lat: -18.142, lng: 178.431},
    {lat: -27.467, lng: 153.027}
  ];
  var flightPath = new google.maps.Polyline({
    path: flightPlanCoordinates,
    geodesic: true,
    strokeColor: '#FF0000',
    strokeOpacity: 1.0,
    strokeWeight: 2
  });

  flightPath.setMap(map);
}

initMap();
    </script>
</body>
</html>

来源：https://stackoverflow.com/questions/34183754/google-map-api-v3-example-from-their-site-doesnt-work-without-an-api-key-but-do

标签

google-maps

google-maps-api-3

polyline

google-polyline