javascript - 如何根据所选半径显示谷歌地图

Question

我有一个里程下拉列表。当我从下拉列表中选择任何值(例如 10 英里)时，我的谷歌地图应显示在该地点的 10 英里范围内。我该如何做到这一点？

<script src="https://maps.googleapis.com/maps/api/js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
      function myMap() {
            var myCenter = new google.maps.LatLng(56.1304, -106.3468);
            var mapProp = { center: myCenter, zoom: 6, scrollwheel: true, draggable: true, mapTypeId: google.maps.MapTypeId.ROADMAP };
            var map = new google.maps.Map(document.getElementById("googleMap"), mapProp);

            marker.setMap(map);
        }

<div id="googleMap" style="height: 100%; width: 100%; position: absolute; top: 0px; left: 0px; "></div>
<div id="searchcontainer" style="position: absolute; z-index: 0; left: 450px; top: 0px;">
    <select id="range" name="range">
        <option value="0">Current Map</option>
        <option value="5">5 Miles</option>
        <option value="10">10 Miles</option>
        <option value="15">15 Miles</option>
        <option value="20">20 Miles</option>
        <option value="25">25 Miles</option>
        <option value="50">50 Miles</option>
        <option value="100">100 Miles</option>
        <option value="250">250 Miles</option>
        <option value="500">500 Miles</option>
    </select>

</div>

Answer 1

一种选择是创建 google.maps.Circle具有正确的中心和所需的半径，然后调用 map.fitBounds(circle.getBounds()) (其中 circle 是圆)。

(请注意，圆的半径以米为单位，因此您需要将输入的英里转换为米)。

var METERS_PER_MILE = 1609.34;

function myMap() {
  var myCenter = new google.maps.LatLng(56.1304, -106.3468);
  var mapProp = {
    center: myCenter,
    zoom: 6,
    scrollwheel: true,
    draggable: true,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };
  var map = new google.maps.Map(document.getElementById("googleMap"), mapProp);
  var circle;
  google.maps.event.addDomListener(document.getElementById('range'), 'change', function(evt) {
    var value = $("#range").val();
    if (circle && circle.setMap) circle.setMap(null);
    circle = new google.maps.Circle({
      center: myCenter,
      radius: value * METERS_PER_MILE,
      map: map
    });
    map.fitBounds(circle.getBounds());
  });
}
google.maps.event.addDomListener(window, 'load', myMap);

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

#googleMap {
  height: 90%;
}

<script src="https://maps.googleapis.com/maps/api/js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="googleMap"></div>
<div id="searchcontainer" style="position: absolute; z-index: 0; left: 450px; top: 0px;">
  <select id="range" name="range">
    <option value="0">Current Map</option>
    <option value="5">5 Miles</option>
    <option value="10">10 Miles</option>
    <option value="15">15 Miles</option>
    <option value="20">20 Miles</option>
    <option value="25">25 Miles</option>
    <option value="50">50 Miles</option>
    <option value="100">100 Miles</option>
    <option value="250">250 Miles</option>
    <option value="500">500 Miles</option>
  </select>
</div>