使用javascript隐藏和显示googlemap中的方向线

Question

我正在使用 directionDisplay.setMap（null）; 删除方向线，但我还想再次显示方向线..我该怎么办？

Answer 1

要再次显示地图，请致电directionDisplay.setMap(map)。 map必须在全局范围内（directionsDisplay）。

＆＃13;

＆＃13;

var directionsDisplay;
var directionsService = new google.maps.DirectionsService();
var map;

function initialize() {
  directionsDisplay = new google.maps.DirectionsRenderer();
  var chicago = new google.maps.LatLng(41.850033, -87.6500523);
  var mapOptions = {
    zoom: 7,
    center: chicago
  };
  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
  directionsDisplay.setMap(map);
  calcRoute();
}

function toggleRoute() {
  if (directionsDisplay.getMap() != null) {
    directionsDisplay.setMap(null);
  } else {
    directionsDisplay.setMap(map);
  }
}

function calcRoute() {
  var start = document.getElementById('start').value;
  var end = document.getElementById('end').value;
  var request = {
    origin: start,
    destination: end,
    travelMode: google.maps.TravelMode.DRIVING
  };
  directionsService.route(request, function(response, status) {
    if (status == google.maps.DirectionsStatus.OK) {
      directionsDisplay.setDirections(response);
    }
  });
}

google.maps.event.addDomListener(window, 'load', initialize);

＆＃13;

html,
body,
#map-canvas {
  height: 100%;
  margin: 0px;
  padding: 0px
}
#panel {
  position: absolute;
  top: 5px;
  left: 50%;
  margin-left: -180px;
  z-index: 5;
  background-color: #fff;
  padding: 5px;
  border: 1px solid #999;
}

＆＃13;

<script src="https://maps.googleapis.com/maps/api/js"></script>
<div id="panel">
  <input type="button" onclick="toggleRoute()" value="toggle" />
  <b>Start: </b>
  <select id="start" onchange="calcRoute();">
    <option value="chicago, il">Chicago</option>
    <option value="st louis, mo">St Louis</option>
    <option value="joplin, mo">Joplin, MO</option>
    <option value="oklahoma city, ok">Oklahoma City</option>
    <option value="amarillo, tx">Amarillo</option>
    <option value="gallup, nm">Gallup, NM</option>
    <option value="flagstaff, az">Flagstaff, AZ</option>
    <option value="winona, az">Winona</option>
    <option value="kingman, az">Kingman</option>
    <option value="barstow, ca">Barstow</option>
    <option value="san bernardino, ca">San Bernardino</option>
    <option value="los angeles, ca">Los Angeles</option>
  </select>
  <b>End: </b>
  <select id="end" onchange="calcRoute();">
    <option value="chicago, il">Chicago</option>
    <option value="st louis, mo" selected="selected">St Louis</option>
    <option value="joplin, mo">Joplin, MO</option>
    <option value="oklahoma city, ok">Oklahoma City</option>
    <option value="amarillo, tx">Amarillo</option>
    <option value="gallup, nm">Gallup, NM</option>
    <option value="flagstaff, az">Flagstaff, AZ</option>
    <option value="winona, az">Winona</option>
    <option value="kingman, az">Kingman</option>
    <option value="barstow, ca">Barstow</option>
    <option value="san bernardino, ca">San Bernardino</option>
    <option value="los angeles, ca">Los Angeles</option>
  </select>
</div>
<div id="map-canvas"></div>

＆＃13;

＆＃13;

＆＃13;