How to set zoom level in google map

问题

Here is the code I have written to add a marker to the google map by providing latitude and longitude. The problem is that I get a very highly zoomed google map. I have tried setting the zoom level to 1 but this has no effect to the very highly zoomed map.

 <script src="http://maps.google.com/maps/api/js?v=3&sensor=false" type="text/javascript"></script>
     <script type="text/javascript">
        var icon = new google.maps.MarkerImage("http://maps.google.com/mapfiles/ms/micons/blue.png",new google.maps.Size(32, 32), new google.maps.Point(0, 0),new google.maps.Point(16, 32));
        var center = null;
        var map = null;
        var currentPopup;
        var bounds = new google.maps.LatLngBounds();
        function addMarker(lat, lng, info) {
            var pt = new google.maps.LatLng(lat, lng);
            bounds.extend(pt);
            var marker = new google.maps.Marker({
                position: pt,
                icon: icon,
                map: map
            });
            var popup = new google.maps.InfoWindow({
                content: info,
                maxWidth: 300
            });
            google.maps.event.addListener(marker, "click", function() {
                if (currentPopup != null) {
                    currentPopup.close();
                    currentPopup = null;
                }
                popup.open(map, marker);
                currentPopup = popup;
            });
            google.maps.event.addListener(popup, "closeclick", function() {
                map.panTo(center);
                currentPopup = null;
            });
        }
        function initMap() {
            map = new google.maps.Map(document.getElementById("map"), {
            center: new google.maps.LatLng(0, 0),
            zoom: 1,
            mapTypeId: google.maps.MapTypeId.ROADMAP,
            mapTypeControl: false,
            mapTypeControlOptions: {
                style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR
            },
            navigationControl: true,
            navigationControlOptions: {
                style: google.maps.NavigationControlStyle.SMALL
            }
        });
        addMarker(27.703402,85.311668,'New Road');
        center = bounds.getCenter();
        map.fitBounds(bounds);

        }
</script>
</head>
<body onload="initMap()" style="margin:0px; border:0px; padding:0px;">
<div id="map"></div>
</body>
</html>

How can i decrease the level of zoom for this case?

回答1:

Your code below is zooming the map to fit the specified bounds:

addMarker(27.703402,85.311668,'New Road');
center = bounds.getCenter();
map.fitBounds(bounds);

If you only have 1 marker and add it to the bounds, that results in the closest zoom possible:

function addMarker(lat, lng, info) {
  var pt = new google.maps.LatLng(lat, lng);
  bounds.extend(pt);
}

If you keep track of the number of markers you have "added" to the map (or extended the bounds with), you can only call fitBounds if that number is greater than one. I usually push the markers into an array (for later use) and test the length of that array.

If you will only ever have one marker, don't use fitBounds. Call setCenter, setZoom with the marker position and your desired zoom level.

function addMarker(lat, lng, info) {
  var pt = new google.maps.LatLng(lat, lng);
  map.setCenter(pt);
  map.setZoom(your desired zoom);
}

回答2:

map.setZoom(zoom:number)

https://developers.google.com/maps/documentation/javascript/reference#Map

回答3:

What you're looking for are the scales for each zoom level. The numbers are in metres. Use these:

20 : 1128.497220

19 : 2256.994440

18 : 4513.988880

17 : 9027.977761

16 : 18055.955520

15 : 36111.911040

14 : 72223.822090

13 : 144447.644200

12 : 288895.288400

11 : 577790.576700

10 : 1155581.153000

9 : 2311162.307000

8 : 4622324.614000

7 : 9244649.227000

6 : 18489298.450000

5 : 36978596.910000

4 : 73957193.820000

3 : 147914387.600000

2 : 295828775.300000

1 : 591657550.500000

回答4:

For zooming your map two level then just add this small code of line map.setZoom(map.getZoom() + 2);

回答5:

Here is a function I use:

var map =  new google.maps.Map(document.getElementById('map'), {
            center: new google.maps.LatLng(52.2, 5),
            mapTypeId: google.maps.MapTypeId.ROADMAP,
            zoom: 7
        });

function zoomTo(level) {
        google.maps.event.addListener(map, 'zoom_changed', function () {
            zoomChangeBoundsListener = google.maps.event.addListener(map, 'bounds_changed', function (event) {
                if (this.getZoom() > level && this.initialZoom == true) {
                    this.setZoom(level);
                    this.initialZoom = false;
                }
                google.maps.event.removeListener(zoomChangeBoundsListener);
            });
        });
    }

回答6:

These methods worked for me, it maybe useful for anyone: MapOptions interface

set min zoom: mMap.setMinZoomPreference(N);

set max zoom: mMap.setMaxZoomPreference(N);

where N can equal to: