Question

我想在地图上显示县行。我找到了几个KML转换后的人口普查数据作为各种分辨率但显示。

我创建了一个Google Site地图并上传了几个KML，包括Google使用的CTA.kml作为示例。 CTA（芝加哥）显示没有问题所以我知道我的网站设置正确。但是当我链接到gz_2010_us_050_00_20m.kml（来自美国人口普查局）或cb_2014_us_county_20m.kml时，没有任何内容。

我认为kml格式对Google地图无效，但我没有收到错误或任何消息。它只是没有出现。

我添加了一个我知道正确的测试脚本，因为我从Google窃取了它。

如果是KML格式问题，是否有人知道美国郡线的KML？

Link to My Site

<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="initial-scale=1.0">
    <meta charset="utf-8">
    <title>KML Layers</title>
    <style>
        html, body {
            height: 100%;
            margin: 0;
            padding: 0;
        }
        #map {
            height: 100%;
        }
    </style>
</head>
<body>
<div id="map"></div>
<script>

    function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
            zoom: 11,
            center: {lat: 41.876, lng: -87.624}
        });

        var ctaLayer = new google.maps.KmlLayer({
            url: 'https://sites.google.com/site/countykmltester/gz_2010_us_050_00_20m.kml',
            map: map
        });
    google.maps.event.addListener(ctaLayer, "status_changed", function() {
       alert( "Kml Status:"+ctaLayer.getStatus());
    });
    }

</script>
<script async defer
        src="https://maps.googleapis.com/maps/api/js?callback=initMap">
</script>
</body>
</html>

Answer 1

将您的KML文件拆分为3个，将每个文件压缩（使其成为KMZ）。他们工作（状态正常）。似乎原始错误消息具有误导性......

name                    | kml size  | kmz size  |
-------------------------------------------------
gz_2010_us_050_00_20m_A | 2,687,331 | 932,267   |
gz_2010_us_050_00_20m_B | 2,633,246 | 836,947   |
gz_2010_us_050_00_20m_C | 2,696,354 | 927,571   |
----- original file -----------------------------
gz_2010_us_050_00_20m   | 8,015,535 | 2,693,916 |

来自SO：Max. Number of Placemarks in KML for Google Maps上的这个问题：

（此信息曾在文档中，但在那里不再可用，link on archive.org ）

updated link to documentation

Google地图中KML渲染的大小和复杂性限制

Google Maps currently has specific limitations to the size and complexity of loaded KML files. Below is a summary of the current limits:

Note: these limits are temporary and are subject to change at any time.

Maximum fetched file size (raw KML, raw GeoRSS, or compressed KMZ)  3MB
Maximum uncompressed KML file size  10MB
Maximum number of Network Links 10
Maximum number of total document-wide features  1,000

proof of concept fiddle

代码段

var geocoder;
var map;

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 11,
    center: {
      lat: 41.876,
      lng: -87.624
    }
  });

  var layerA = new google.maps.KmlLayer({
    url: 'http://www.geocodezip.com/geoxml3_test/kmz/gz_2010_us_050_00_20m_A.kmz',
    map: map
  });
  google.maps.event.addListener(layerA, 'status_changed', function() {
    document.getElementById('status').innerHTML += "layerA:" + layerA.getStatus() + "<br>";
  })
  var layerB = new google.maps.KmlLayer({
    url: 'http://www.geocodezip.com/geoxml3_test/kmz/gz_2010_us_050_00_20m_B.kmz',
    map: map
  });
  google.maps.event.addListener(layerB, 'status_changed', function() {
    document.getElementById('status').innerHTML += "layerB:" + layerB.getStatus() + "<br>";
  })
  var layerC = new google.maps.KmlLayer({
    url: 'http://www.geocodezip.com/geoxml3_test/kmz/gz_2010_us_050_00_20m_C.kmz',
    map: map
  });
  google.maps.event.addListener(layerC, 'status_changed', function() {
    document.getElementById('status').innerHTML += "layerC:" + layerC.getStatus() + "<br>";
  })
}
google.maps.event.addDomListener(window, "load", initMap);

html,
body,
#map {
  height: 100%;
  width: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://maps.googleapis.com/maps/api/js"></script>
<div id="status"></div>
<div id="map"></div>

适用于Google地图的县KML数据

1 个答案: