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google-maps-api-3 - 谷歌地图方向服务给出错误的结果

问题描述

我正在尝试使用 googles DirectionsService 获取以英里为单位的距离和估计时间。它有点工作，但我知道它给我的结果是不正确的。距离和时间太短？我需要驾驶模式下的结果。代码示例是：

HTML

<input id="s_lat" value="52.441334" />
<input id="s_lng" value="-1.654737" />
<input id="d_lat" value="52.450439" />
<input id="d_lng" value="-1.729660" />

JS

var n_start = s_lat + ',' + s_lng;
var n_end = d_lat + ',' + d_lng;

function getdistance() {
    var directionsService = new google.maps.DirectionsService();

    var request = {
        origin      : n_start,
        destination : n_end,
        travelMode  : google.maps.TravelMode.DRIVING,
        unitSystem: google.maps.UnitSystem.METRIC,
        durationInTraffic: true
    };

    directionsService.route(request, function(response, status) {
        if ( status == google.maps.DirectionsStatus.OK ) {

            alert (response.routes[0].legs[0].duration.value);
            alert (response.routes[0].legs[0].distance.value);
        }
        else {
            // oops, there's no route between these two locations

        }
    });

}

标签： google-maps-api-3map-directions

解决方案

我用发布的代码得到的结果是NOT_FOUND，我没有距离。逗号分隔的字符串不是 agoogle.maps.LatLng或 a google.maps.LatLngLiteral，它被视为地址并在返回结果之前进行地理编码。

这个：

var n_start = s_lat + ',' + s_lng;
var n_end = d_lat + ',' + d_lng;

应该是（google.maps.LatLngLiteral）：

var n_start = {lat: parseFloat(s_lat.value), lng: parseFloat(s_lng.value)}; 
var n_end = {lat: parseFloat(d_lat.value), lng: parseFloat(d_lng.value)};

或 ( google.maps.LatLng)：

var n_start = new google.maps.LatLng(s_lat.value,s_lng.value);
var n_end = new google.maps.LatLng(d_lat.value,d_lng.value);

概念证明小提琴

在此处输入图像描述

代码片段：

function initMap() {
  var n_start = new google.maps.LatLng(s_lat.value,s_lng.value);
  var n_end = new google.maps.LatLng(d_lat.value,d_lng.value);
 

  function getdistance() {
    var directionsService = new google.maps.DirectionsService();

    var request = {
      origin: n_start,
      destination: n_end,
      travelMode: google.maps.TravelMode.DRIVING,
      unitSystem: google.maps.UnitSystem.METRIC,
      durationInTraffic: true
    };
    console.log(JSON.stringify(request));
    directionsService.route(request, function(response, status) {
      if (status == google.maps.DirectionsStatus.OK) {

        console.log("duration=" + response.routes[0].legs[0].duration.value + " seconds");
        console.log("distance=" + response.routes[0].legs[0].distance.value + " meters");
        document.getElementById('result').innerHTML = "distance=" + (response.routes[0].legs[0].distance.value / 1000).toFixed(2) + " km<br>duration=" + (response.routes[0].legs[0].duration.value / 60).toFixed(2) + " minutes";
        new google.maps.DirectionsRenderer({
          map: new google.maps.Map(document.getElementById('map')),
          directions: response
        })
      } else {
        window.alert('Directions request failed due to ' + status);

      }
    });

  }
  getdistance();
}
#map {
  height: 100%;
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}
<input id="s_lat" value="52.441334" />
<input id="s_lng" value="-1.654737" />
<input id="d_lat" value="52.450439" />
<input id="d_lng" value="-1.729660" /><br>
<div id="result"></div>
<div id="map"></div>
<!-- Replace the value of the key parameter with your own API key. -->
<script async defer src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap"></script>

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