javascript - Google API及其自身函数directionService的错误结果

Question

我遇到了这个问题，当我加载页面并插入起点和终点时，单击“定位”按钮后，它在谷歌地图中没有显示任何内容，因为它说响应不是对象，所以我尝试用 console.log 标记它，它显示 Response=null ，但是如果我重新加载页面并快速单击 Locate ，那么它会绘制路线。

这是代码

function init(){
    var latlng = new google.maps.LatLng(40.635636, 17.942414);
    var mapOptions = { zoom: 12, center: latlng  };
    map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
}

function updateMap(){
    init();

    var originGeocoder = new google.maps.Geocoder();
    var destinationGeocoder = new google.maps.Geocoder();

    var origin = document.getElementById( "origin" ).value + " Brindisi 72100";
    var destination = document.getElementById( "destination" ).value + " Brindisi 72100";


    var directionsService2 = new google.maps.DirectionsService();

    originGeocoder.geocode( { 'address': origin }, function(results, status) {
        if ( status == google.maps.GeocoderStatus.OK ) {
            var startLatLng = results[0].geometry.location;
            var oLat = startLatLng.lat();
            var oLng = startLatLng.lng();
            document.getElementById('cStart').innerHTML = oLat + " " + oLng;
        }
        else{
            alert("Geocode was not successful for the following reason: " + status);
        }      
    });

    //Chiamata asincrona alle API per ottenere Lat e Lng dell' indirizzo di destinazione
    destinationGeocoder.geocode( { 'address': destination }, function(results, status) {
        if ( status == google.maps.GeocoderStatus.OK ) {
            var destLatLng = results[0].geometry.location;
            var dLat = destLatLng.lat();
            var dLng = destLatLng.lng();
            document.getElementById('cDestination').innerHTML = typeof dLat;
            document.getElementById('cDestination').innerHTML = dLat + " " + dLng;
        }
        else{
            alert("Geocode was not successful for the following reason: " + status);
        }        
    });

    //Salva in req[] le varie distanze tra le paline e la destinazione
    singleObjToStop(origin,destination,function(paline,req,reqO){
        console.log("1");
        //Trova la palina più vicina alla destinazione
        calcSingleDis(paline,req,reqO,function(w2,w1){
            console.log("2");
            //Disegna i waypoints(?)
            reqEnd(origin,destination,w1,w2,function(request){
                console.log("3");
                directionsService2.route(request, function(response, status) {
                    console.log("4");
                    console.log(response);
                    if (status == google.maps.DirectionsStatus.OK) {
                        directionsDisplay.setDirections(response);
                        var route = response.routes[0];
                        var summaryPanel = document.getElementById("distance");
                        summaryPanel.innerHTML = "";
                        // For each route, display summary information.
                        for (var i = 0; i < route.legs.length; i++) {
                            var routeSegment = i + 1;
                            summaryPanel.innerHTML += "<b>Route Segment: " + routeSegment + "</b><br />";
                            summaryPanel.innerHTML += route.legs[i].start_address + " to ";
                            summaryPanel.innerHTML += route.legs[i].end_address + "<br />";
                            summaryPanel.innerHTML += route.legs[i].distance.text + " ";
                            summaryPanel.innerHTML += route.legs[i].duration.text +  "<br /><br />" ;
                        }
                        computeTotalDistance(response);
                    }
                    else{
                        console.log("ENTRA QUA STRONZO");
                        console.log("Fermata partenza = " + w1);
                        console.log("Fermata arrivo = " + w2);
                    }
                });
                directionsDisplay.setMap(map);
            });
        });
    });
}

function singleObjToStop(origin,destination,callback){
    var data=<?php echo $data; ?>;
    var a,b,i=0;
    var paline = new Array();
    var req = new Array(); 
    var reqO = new Array();
    var num = <?php echo $n; ?>;
    $.each(data, function(fieldName, fieldValue) {
        a=fieldValue.geoLat;
        b=fieldValue.geoLong;
        a=parseFloat(a);
        b=parseFloat(b);
        paline[i]=new google.maps.LatLng(a,b);

        req[i] = {
            origin:paline[i],
            destination:destination,
            travelMode: google.maps.TravelMode.WALKING
        };

        reqO[i] = {
            origin:origin,
            destination:paline[i],
            travelMode: google.maps.TravelMode.WALKING
        };

        i++;
        if(i==num){
            callback(paline,req,reqO);
        }
    });
}

function calcSingleDis(paline, req, reqO, callback) {
    var directionsService = new google.maps.DirectionsService();
    var c = 10000000;
    var w2 = new google.maps.LatLng(0, 0);
    var w1 = new google.maps.LatLng(0, 0);
    var num = <?php echo $n; ?>;
    var j = (num - 1);
    var t;

    var cO = 10000000;
    var numO = <?php echo $n; ?>;
    var jO = 0;
    for (j = 0; j < num; j++) {
        t = 0;
        directionsService.route(req[j], function(response, status) {
            if (status == google.maps.DirectionsStatus.OK) {
                //directionsDisplay.setDirections(response);
                var troute = response.routes[0];
                var dis = parseFloat((troute.legs[0].distance.text).replace(",", "."));

                document.getElementById('test').innerHTML = dis;

                //se distanza minore di quella minore trovata fin ora la cambia
                if (dis < c) {
                    w2 = paline[j - num];
                    c = dis;
                }

                if (t == (num - 1)) {
                    console.log("QUA ENTRA LOL");

                    for (jO = 0; jO < numO; jO++) {
                        console.log("E NON ENTRA MANNAC");
                        t = 0;
                        directionsService.route(reqO[jO], function(response, status) {
                            if (status == google.maps.DirectionsStatus.OK) {
                                console.log("E NON ENTRA MANNAC22222");
                                //directionsDisplay.setDirections(response);
                                var troute = response.routes[0];
                                var disO = parseFloat((troute.legs[0].distance.text).replace(",", "."));

                                document.getElementById('test').innerHTML = dis;

                                //se distanza minore di quella minore trovata fin ora la cambia
                                if (disO < cO) {
                                    w1 = paline[jO - numO];
                                    cO = disO;
                                }

                                if (t == (numO - 1)) {
                                    console.log("W1 = " + w1);
                                    console.log(response);
                                    callback(w2, w1);

                                }
                            }
                            jO++;
                            t++;
                        });
                    }

                }
            }
            j++;
            t++;
        });
    }
}

function reqEnd(origin,destination,w1,w2,callback){
    var request = {
        origin:origin,
        destination:destination,
          waypoints: [{location: w1} , {location: w2}],
          //waypoints: [{location: w2}],
          optimizeWaypoints: true,
        travelMode: google.maps.DirectionsTravelMode.WALKING
    };
    callback(request);
}

function computeTotalDistance(result) {
    var totalDist = 0;
    var totalTime = 0;
    var myroute = result.routes[0];
    for (i = 0; i < myroute.legs.length; i++) {
        totalDist += myroute.legs[i].distance.value;
        totalTime += myroute.legs[i].duration.value;   
    }
    totalDist = totalDist / 1000.
    document.getElementById("total").innerHTML = "total distance is: "+ totalDist + " km<br>total time is: " + (totalTime / 60).toFixed(2) + " minutes";
}

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

Answer 1

该问题与 Google Maps API v3 可以使用的查询限制有关。您可以在这里查看:https://developers.google.com/maps/documentation/business/faq#google_maps_api_services

您可能会使用您的程序向 API 发出大量请求，但正如您从 Google Q&A 中看到的那样，您的限制非常严格。

Applications should throttle requests to avoid exceeding usage limits, bearing in mind these apply to each client ID regardless of how many IP addresses the requests are sent from.

You can throttle requests by putting them through a queue that keeps track of when are requests sent. With a rate limit or 10 QPS (queries per second), on sending the 11th request your application should check the timestamp of the first request and wait until 1 second has passed. The same should be applied to daily limits.

Even if throttling is implemented correctly applications should watch out for responses with status code OVER_QUERY_LIMIT. If such response is received, use the pause-and-retry mechanism explained in the Usage limits exceeded section above to detect which limit has been exceeded.

您可能会发现有用:How do I Geocode 20 addresses without receiving an OVER_QUERY_LIMIT response?