如何在 Google 地图中显示存储为字符串的多边形坐标？

Question

我的 MySQL 数据库中存储了一串坐标，我无法在 Google 地图中显示，因为它需要是 LatLng 对象：

'(55.46701996570562, 11.983202375732418),(55.46604683879285, 11.982086576782223),(55.465316977846335, 11.983803190551754),(55.465900867684354, 11.985863127075191)'

我知道我可以将这些坐标存储为 POLYGON 数据类型，但由于某些其他原因（与此处提及它们无关）我不想这样做。

当尝试在下面的代码中使用该坐标字符串时，它显示错误：

const polygon_coords = '(55.46701996570562, 11.983202375732418),(55.46604683879285, 11.982086576782223),(55.465316977846335, 11.983803190551754),(55.465900867684354, 11.985863127075191)';

const coords = new google.maps.Polygon({
    paths: polygon_coords,
    strokeColor: "#FF0000",
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: "#FF0000",
    fillOpacity: 0.35,
    editable: true
});

错误：

InvalidValueError: at index 0: not a LatLng or LatLngLiteral with finite coordinates: not an Object

知道如何通过 Google 将坐标字符串转换为可识别的格式，例如 LatLng 或 LatLngLiteral ？

Answer 1

您可以像这样将您的坐标转换为 LatLng[] 坐标：

const polygon_coords = `(55.46701996570562, 11.983202375732418),
  (55.46604683879285, 11.982086576782223),
  (55.465316977846335, 11.983803190551754),
  (55.465900867684354, 11.985863127075191)`

  // Surround with [] to make an outer array.
  // and replace ( and ) with [ and ] to make inner arrays
  const jsonArray = `[
    ${polygon_coords.replace(/\)/g, ']')
                    .replace(/\(/g, '[')}
  ]`
  console.log(`Your json array: \n${jsonArray}\n`)

  const parsedCoords = JSON.parse(jsonArray)
  console.log(`${parsedCoords}\n`)

  // Assuming your coords are (lat,lng) order
  const latLngs = parsedCoords.map(pair => ({lat: pair[0], lng: pair[1]}))

  console.log(latLngs)
  const coords = new google.maps.Polygon({
    paths: latLngs,
    strokeColor: "#FF0000",
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: "#FF0000",
    fillOpacity: 0.35,
    editable: true
  });

Answer 2

将 polygon_coords 字符串解析为其单独的坐标，使用它们创建 google.maps.LatLngLiteralgoogle.maps. or google.maps.LatLng` 对象

var polygon_coords_str = '(55.46701996570562, 11.983202375732418),(55.46604683879285, 11.982086576782223),(55.465316977846335, 11.983803190551754),(55.465900867684354, 11.985863127075191)';
  polygon_coords_str = polygon_coords_str.substring(1, polygon_coords_str.length - 1);
  polygon_coords_str = polygon_coords_str.split("),(");
  var polygon_coords = [];
  for (var i = 0; i < polygon_coords_str.length; i++) {
    polygon_coords.push({ // create a google.maps.LatLngLiteral
      // assume original data is (lat, lng)
      lat: parseFloat(polygon_coords_str[i].split(',')[0]),
      lng: parseFloat(polygon_coords_str[i].split(',')[1])
    })
  }

使用这些创建多边形：

  const coords = new google.maps.Polygon({
    paths: polygon_coords,
    strokeColor: "#FF0000",
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: "#FF0000",
    fillOpacity: 0.35,
    editable: true
  });

proof of concept fiddle

代码片段：

// This example creates a simple polygon representing the Bermuda Triangle.
function initMap() {
  const map = new google.maps.Map(document.getElementById("map"), {
    zoom: 5,
    center: {
      lat: 55.4,
      lng: 11.9
    },
    mapTypeId: "terrain",
  });
  var polygon_coords_str = '(55.46701996570562, 11.983202375732418),(55.46604683879285, 11.982086576782223),(55.465316977846335, 11.983803190551754),(55.465900867684354, 11.985863127075191)';
  polygon_coords_str = polygon_coords_str.substring(1, polygon_coords_str.length - 1);
  polygon_coords_str = polygon_coords_str.split("),(");
  // console.log(polygon_coords_str);
  var polygon_coords = [];
  for (var i = 0; i < polygon_coords_str.length; i++) {
    polygon_coords.push({
      lat: parseFloat(polygon_coords_str[i].split(',')[0]),
      lng: parseFloat(polygon_coords_str[i].split(',')[1])
    })
  }
  console.log("polygon_coords.length=" + polygon_coords.length);
  for (var i = 0; i < polygon_coords.length; i++) {
    console.log(polygon_coords[i]);
  }
  const coords = new google.maps.Polygon({
    paths: polygon_coords,
    strokeColor: "#FF0000",
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: "#FF0000",
    fillOpacity: 0.35,
    editable: true
  });
  var bounds = new google.maps.LatLngBounds();
  for (var i = 0; i < coords.getPath().getLength(); i++)
    bounds.extend(coords.getPath().getAt(i));
  map.fitBounds(bounds);
  coords.setMap(map);
}

/* Always set the map height explicitly to define the size of the div
       * element that contains the map. */

#map {
  height: 100%;
}


/* Optional: Makes the sample page fill the window. */

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

<!DOCTYPE html>
<html>

<head>
  <title>Simple Polygon</title>
  <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
  <!-- jsFiddle will insert css and js -->
</head>

<body>
  <div id="map"></div>

  <!-- Async script executes immediately and must be after any DOM elements used in callback. -->
  <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap&v=weekly&channel=2" async></script>
</body>

</html>

如何在 Google 地图中显示存储为字符串的多边形坐标？

How to display in Google Maps polygon coordinates stored as string?

javascript

google-maps

google-maps-api-3

polygon