javascript - Google Maps API v3 热图错误 : "Cannot read property ' HeatmapLayer' of undefined"

Question

我正在尝试将 Heatmaps 图层加载到我的谷歌地图上，但出于某种原因，我一直收到错误消息“无法读取未定义的属性‘HeatmapLayer’。”

map = new google.maps.Map(document.getElementById("gmaps"),{
    zoom: 11,
    center: new google.maps.LatLng(39.788403, -86.19990800000001),
    mapTypeControl: false,
    streetViewControl: false,
    mapTypeId: google.maps.MapTypeId.ROADMAP,
    panControl: false
});

heatMapData = [
new google.maps.LatLng(39.77745056152344, -86.10900878906250),
new google.maps.LatLng(39.82060623168945, -86.17008972167969),
new google.maps.LatLng(39.77947616577148, -86.17008972167969),
new google.maps.LatLng(39.82987594604492, -86.13955688476562),
new google.maps.LatLng(39.74195098876953, -86.12429046630860)
];
heatmap = new google.maps.visualization.HeatmapLayer({
    data: heatMapData,
    map: map
});

这是 jsFiddle:http://jsfiddle.net/9HQ2a/3/

Answer 1

在加载 google maps js 时将可视化库添加到 URL。

<script async defer src="https://maps.googleapis.com/maps/api/js?v=3.exp&libraries=visualization"></script>