Google Maps JavaScript API v3 在两个位置之间绘制线条

Google Maps JavaScript API v3 drawing line between two location

本文关键字：位置 两个 之间 绘制 JavaScript Maps API v3 Google      更新时间：2023-09-26

请帮帮我，我真的坚持了！我的代码是：

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Geocoding service</title>
    <style>
      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;
      }
    </style>
    <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
    <script>
var geocoder;
var map;
function initialize() {
  geocoder = new google.maps.Geocoder();
  var latlng = new google.maps.LatLng(-34.397, 150.644);
  var mapOptions = {
    zoom: 8,
    center: latlng
  }
  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
}
function codeAddress() {
  var address = document.getElementById('address').value;
  geocoder.geocode( { 'address': address}, function(results, status) {
    if (status == google.maps.GeocoderStatus.OK) {
      map.setCenter(results[0].geometry.location);
      var marker = new google.maps.Marker({
          map: map,
          position: results[0].geometry.location
      });
    } else {
      alert('Geocode was not successful for the following reason: ' + status);
    }
  });
  var address2 = document.getElementById('address2').value;
  geocoder.geocode( { 'address2': address2}, function(results2, status2) {
    if (status2 == google.maps.GeocoderStatus.OK) {
      var marker2 = new google.maps.Marker({
          map: map,
          position: results2[0].geometry.location
      });
    } else {
      alert('Geocode was not successful for the following reason: ' + status);
    }
  });
  var myTrip = [address,address2];
    var flightPath = new google.maps.Polyline({
      path:myTrip,
      strokeColor:"#00F",
      strokeOpacity:0.8,
      strokeWeight:2
  });
flightPath.setMap(map);
}

google.maps.event.addDomListener(window, 'load', initialize);
    </script>
  </head>
  <body>
    <div id="panel">
      <input id="address" type="textbox" value="address 1">
      <input id="address2" type="textbox" value="address 2">
      <input type="button" value="Geocode" onclick="codeAddress()">
    </div>
    <div id="map-canvas"></div>
  </body>
</html>

我想在输入中输入两个地址，分别将其转换为经度/经度，在地图上放置两个标记并在它们之间画一条直线！我的代码不起作用，它只显示第一个地址，仅此而已......提前谢谢你！

好吧，似乎您至少存在语法错误（ address2 ），因为您定义了：

geocoder.geocode( { 'address2': address2}, function(results2, status2) {

而不是：

geocoder.geocode( { 'address': address2}, function(results2, status2) {
但是，在

定义实际折线时也存在错误，因为地理编码是异步的，因此您无法在对线进行地理编码后调用折线的创建，而是需要创建单独的方法或类似的回调功能，该功能在地理编码完成后调用。否则，您只是在处理undefined值。

因此，我决定添加名为 displayMarkers() 的方法，该方法从每个地理编码请求中调用，进而检查所有地址是否都经过地理编码并采取相应的行动。 以下是更改的代码：（它也可以在不刷新页面的情况下工作，您可以尝试连续搜索多个地址）。

var geocoder;
var map;
var geocodeMarkers = [];
var flightPath;
function initialize() {
  geocoder = new google.maps.Geocoder();
  var latlng = new google.maps.LatLng(-34.397, 150.644);
  var mapOptions = {
    zoom: 8,
    center: latlng
  }
  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
}
function codeAddress() {
  // Emptying last addresses because of recent query
  for(var i = 0; i < geocodeMarkers.length; i++) {
     geocodeMarkers[i].setMap(null);
  }  
  // Empty array
  geocodeMarkers.length = 0;
  // Empty flight route
  if(typeof flightPath !== "undefined") {
     flightPath.setMap(null);
     flightPath = undefined;
  }  
  var address = document.getElementById('address').value;
  geocoder.geocode( { 'address': address}, function(results, status) {
    if (status == google.maps.GeocoderStatus.OK) {
        // Adding marker to geocodeMarkers
        geocodeMarkers.push(
            new google.maps.Marker({
              position: results[0].geometry.location
            })
        );
        // Attempting to display
        displayMarkers();
        } else {
          alert('Geocode was not successful for the following reason: ' + status);
        }
  });
  var address2 = document.getElementById('address2').value;
  geocoder.geocode( { 'address': address2 }, function(results2, status2) {
    if (status2 == google.maps.GeocoderStatus.OK) {
       // Adding marker to geocodeMarkers
       geocodeMarkers.push(
           new google.maps.Marker({
               position: results2[0].geometry.location
           })
       );
       // Attempting to display
       displayMarkers();
    } else {
      alert('Geocode was not successful for the following reason: ' + status);
    }
 });

}
function displayMarkers() {
  // If geocoded successfully for both addresses
  if(geocodeMarkers.length === 2) {
    // Bounds for the markers so map can be placed properly
    var bounds = new google.maps.LatLngBounds(
       geocodeMarkers[0].getPosition(),
       geocodeMarkers[1].getPosition()
    );
    // Fit map to bounds
    map.fitBounds(bounds);
    // Setting markers to map
    geocodeMarkers[0].setMap(map);
    geocodeMarkers[1].setMap(map);    
    flightPath = new google.maps.Polyline({
       path: [geocodeMarkers[0].getPosition(), geocodeMarkers[1].getPosition()],
       strokeColor:"#00F",
       strokeOpacity:0.8,
       strokeWeight:2,
       map: map
    });
  }
}
google.maps.event.addDomListener(window, 'load', initialize);

工作 jsfiddle 示例：js 小提琴演示 1

编辑：

经过进一步的评论，本主题的作者希望将地图居中放在第一个地理编码标记上。它是通过更改以下行来实现的：

// Bounds for the markers so map can be placed properly
var bounds = new google.maps.LatLngBounds(
   geocodeMarkers[0].getPosition(),
   geocodeMarkers[1].getPosition()
);
// Fit map to bounds
map.fitBounds(bounds);

自：

// Center map to first geocoded location
map.setCenter(geocodeMarkers[0].getPosition());

为此工作 jsfiddle：js 小提琴演示 2

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