javascript - 如何在谷歌地图中设置缩放级别

Question

这是我编写的通过提供纬度和经度向谷歌地图添加标记的代码。问题是我得到了一个高度放大的谷歌地图。我尝试将缩放级别设置为 1，但这对高度缩放的地图没有影响。

 <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>

在这种情况下，如何降低缩放级别？

score 123 · Accepted Answer

您下面的代码正在缩放地图以适应指定的范围：

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

如果您只有 1 个标记并将其添加到边界，则可能会导致最接近的缩放：

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

如果您跟踪已“添加”到地图（或扩展边界）的标记数量，则只有在该数字大于 1 时才能调用 fitBounds。我通常将标记推入一个数组（供以后使用）并测试该数组的长度。

如果您只有一个标记，请不要使用 fitBounds。使用标记位置和所需的缩放级别setCenter调用。setZoom

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

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

<html>

<head>
  <script src="http://maps.google.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk" 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);
      map.setCenter(pt);
      map.setZoom(5);
      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>

score 28 · Accepted Answer

28

map.setZoom(zoom:number)

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

于 2012-07-12T14:40:16.200 回答

score 21 · Accepted Answer

您正在寻找的是每个缩放级别的比例。数字以米为单位。使用这些：

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

score 14 · Accepted Answer

14

要将地图放大两个级别，请添加这一小行代码，

map.setZoom(map.getZoom() + 2);

于 2013-07-05T13:57:46.727 回答

score 6 · Accepted Answer

这是我使用的一个功能：

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);
            });
        });
    }

score 2 · Accepted Answer

这些方法对我有用，它可能对任何人都有用： MapOptions interface

设置最小缩放： mMap.setMinZoomPreference(N);

设置最大缩放： mMap.setMaxZoomPreference(N);

其中 N 可以等于：