如何設置Google Map縮放級別以在中心顯示所有標記和用戶？

Question

我正在創建一個運輸應用程序，用戶可以在其中單擊各種驅動程序來選擇它們。

我從數據庫放置了不同的驅動程序：

function multimarker(map) {
    jQuery.ajax({
        url: baseurl + "getdriverlocation.php",

        async: true,
        success: function (data) {
            var myArray = jQuery.parseJSON(data); // instead of JSON.parse(data)

            jQuery(myArray).each(function (index, element) {
                driverlat = element.driver_lat;
                driverlng = element.driver_lng;
                loginid = element.loginid;
                locations.push([driverlat, driverlng, loginid])
            });

            var bounds1 = new google.maps.LatLngBounds();

            for (i = 0; i < locations.length; i++) {

                var latlng1 = new google.maps.LatLng(locations[i][0], locations[i][1]);
                if (google.maps.geometry.spherical.computeDistanceBetween(latlng1, map.getCenter()) < 30000) {
                    drivermarker = new google.maps.Marker({
                        position: latlng1
                    });
                    drivermarker.setMap(map);

                    google.maps.event.addListener(drivermarker, 'click', (function (drivermarker, i) {
                        return function () {
                            driverdetail(locations[i][2]);
                        }
                    })(drivermarker, i));
                    bounds1.extend(latlng1);
                    map.fitBounds(bounds1);
                }
            }
        }
    });
}

並將用戶設置為當前位置：

function currentpostionmap() {
    $(document).on("pageshow", "#inside123", function () {
         
        if (navigator.geolocation) {
                    
            function success(pos) {            
                userClat = pos.coords.latitude;
                userClng = pos.coords.longitude;
                var latlng = new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude); 
                var myOptions = {            
                    zoom: 15,
                                center: latlng,
                                mapTypeId: google.maps.MapTypeId.ROADMAP        
                };        
                map = new google.maps.Map(document.getElementById("map"), myOptions);      
                var image123 = 'https:///developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png';
                marker = new google.maps.Marker({            
                    position: latlng,
                    map: map,
                    icon: image123                
                });
                var infowindow1 = new google.maps.InfoWindow();

                google.maps.event.addListener(marker, 'click', (function (marker, i) {
                    return function () {
                        infowindow1.setContent('YOU');
                        infowindow1.open(map, marker);
                        map.setZoom(20);
                        map.setCenter(marker.getPosition());

                    }
                })(marker));
                multimarker(map);
            }        
            function fail(error) {          
                var latlng = new google.maps.LatLng(18.5204, 73.8567); 
                var myOptions = {            
                    zoom: 10,
                                center: latlng,
                                mapTypeId: google.maps.MapTypeId.ROADMAP        
                };        
                map = new google.maps.Map(document.getElementById("map"), myOptions);             
                marker = new google.maps.Marker({            
                    position: latlng,
                                map: map                   
                });
            }       
            navigator.geolocation.getCurrentPosition(success, fail, {
                maximumAge: 500000,
                enableHighAccuracy: true,
                timeout: 6000
            });    
        }
    });
} 

如何將用戶設置在中心並以這樣的方式設置地圖，使得用戶可以在中心查看不同位置的所有標記？

注意：使用當前代碼，我面臨一個問題，即如果驅動程序離用戶很遠，則只能在中心查看驅動程序。 用戶必須拖動地圖才能看到他們的位置。

Answer 1

您需要執行一個多步驟過程。

1. 將所有標記和“用戶”位置添加到google.maps.LatLngBounds對象
2. 使地圖適合該范圍。
3. 將地圖中心設置為用戶的位置。
4. 如果沒有一次縮小，請確認所有標記仍在視圖中（當前地圖邊界包含計算出的邊界）。

代碼段 ：

 var geocoder; var map; var locations = [ [-33.890542, 151.274856, 'Bondi Beach'], [-33.923036, 151.259052, 'Coogee Beach'], [-34.028249, 151.157507, 'Cronulla Beach'], [-33.80010128657071, 151.28747820854187, 'Manly Beach'], [-33.950198, 151.259302, 'Maroubra Beach'] ] function initialize() { var pos = { coords: { latitude: -33.42502, //-33.8674869, longitude: 151.3422193 // 151.2069902 } } userClat = pos.coords.latitude; userClng = pos.coords.longitude; var latlng = new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude); var myOptions = { zoom: 15, center: latlng, mapTypeId: google.maps.MapTypeId.ROADMAP }; map = new google.maps.Map(document.getElementById("map"), myOptions); var image123 = 'https:///developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png'; // var bounds = new google.maps.LatLngBounds(); marker = new google.maps.Marker({ position: latlng, map: map, icon: image123 }); var infowindow1 = new google.maps.InfoWindow(); google.maps.event.addListener(marker, 'click', (function(marker, i) { return function() { infowindow1.setContent('YOU'); infowindow1.open(map, marker); map.setZoom(20); map.setCenter(marker.getPosition()); } })(marker)); multimarker(map, latlng, infowindow1); } function multimarker(map, userloc, infowindow) { var bounds1 = new google.maps.LatLngBounds(); for (i = 0; i < locations.length; i++) { var latlng1 = new google.maps.LatLng(locations[i][0], locations[i][1]); // if (google.maps.geometry.spherical.computeDistanceBetween(latlng1, map.getCenter()) < 30000) { drivermarker = new google.maps.Marker({ position: latlng1, icon: "http://maps.google.com/mapfiles/ms/micons/blue.png", map: map }); drivermarker.setMap(map); google.maps.event.addListener(drivermarker, 'click', (function(marker, i) { return function(evt) { infowindow.setContent(locations[i][2]); infowindow.open(map, marker); } })(drivermarker, i)); bounds1.extend(latlng1); map.fitBounds(bounds1); // } } bounds1.extend(userloc); map.fitBounds(bounds1); // wait for the bounds change to happen google.maps.event.addListenerOnce(map, 'bounds_changed', function() { // set the center on the user map.setCenter(userloc); // wait for the center to change google.maps.event.addListenerOnce(map, 'bounds_changed', function() { // check to see if all the markers are still in bounds if ((!map.getBounds().contains(bounds1.getNorthEast())) || (!map.getBounds().contains(bounds1.getSouthWest()))) { // if not zoom out one level console.log(map.getZoom() + " zoom-1 will be " + (map.getZoom() - 1)); map.setZoom(map.getZoom() - 1); } }); }); } google.maps.event.addDomListener(window, "load", initialize); 

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

 <script src="https://maps.googleapis.com/maps/api/js"></script> <div id="map"></div>