Google地图接口API之地图事件(四)
演示几个地图事件:
1. 点击标记缩放地图
仍然使用上一遍文章使用的英国伦敦的地图。点用户点击标记时实现缩放地图的功能(点击标记时绑定地图缩放事件)。
代码如下：
<html> <head> <script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false"> </script> <script> var myCenter=new google.maps.LatLng(51.508742,-0.120850); function initialize() { var mapProp = { center: myCenter, zoom:5, mapTypeId: google.maps.MapTypeId.ROADMAP }; var map = new google.maps.Map(document.getElementById("googleMap"),mapProp); var marker = new google.maps.Marker({ position: myCenter, title:'Click to zoom' }); marker.setMap(map); // Zoom to 9 when clicking on marker google.maps.event.addListener(marker,'click',function() { map.setZoom(9); map.setCenter(marker.getPosition()); }); } google.maps.event.addDomListener(window, 'load', initialize); </script> </head> <body> <div id="googleMap" style="width:500px;height:380px;"></div> </body> </html>
使用 addListener() 事件处理程序来注册事件的监听。该方法使用一个对象，一个事件来监听，当指定的事件发生时 函数将被调用。
2. 重置标记
通过给地图添加事件处理程序来改变 'center' 属性，以下代码使用 center_changed 事件在3秒后标记自动移到中心点,代码如下：
<html> <head> <script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false"> </script> <script> var myCenter=new google.maps.LatLng(51.508742,-0.120850); function initialize() { var mapProp = { center: myCenter, zoom:5, mapTypeId: google.maps.MapTypeId.ROADMAP }; var map = new google.maps.Map(document.getElementById("googleMap"),mapProp); var marker = new google.maps.Marker({ position: myCenter, title:'Click to zoom' }); marker.setMap(map); // Zoom to 9 when clicking on marker google.maps.event.addListener(marker,'click',function() { map.setZoom(9); map.setCenter(marker.getPosition()); }); google.maps.event.addListener(map,'center_changed',function() { // 3 seconds after the center of the map has changed, pan back to the marker window.setTimeout(function() { map.panTo(marker.getPosition()); },3000); }); } google.maps.event.addDomListener(window, 'load', initialize); </script> </head> <body> <div id="googleMap" style="width:500px;height:380px;"></div> </body> </html>
3. 点击标记时打开信息窗口。
点击标记在信息窗口显示一些文本信息，代码如下:
<html> <head> <script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false"> </script> <script> var myCenter=new google.maps.LatLng(51.508742,-0.120850); function initialize() { var mapProp = { center:myCenter, zoom:5, mapTypeId:google.maps.MapTypeId.ROADMAP }; var map=new google.maps.Map(document.getElementById("googleMap"),mapProp); var marker=new google.maps.Marker({ position:myCenter, }); marker.setMap(map); var infowindow = new google.maps.InfoWindow({ content:"Hello World!" }); google.maps.event.addListener(marker, 'click', function() { infowindow.open(map,marker); }); } google.maps.event.addDomListener(window, 'load', initialize); </script> </head> <body> <div id="googleMap" style="width:500px;height:380px;"></div> </body> </html>
4. 设置标记及打开每个标记的信息窗口
当用户点击地图时执行一个窗口,用户点击地图某个位置时,在指定位置上放置一个标记，并弹出信息窗口,代码如下所示：
<html> <head> <script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false"> </script> <script> var map; var myCenter=new google.maps.LatLng(51.508742,-0.120850); function initialize() { var mapProp = { center:myCenter, zoom:5, mapTypeId:google.maps.MapTypeId.ROADMAP }; map = new google.maps.Map(document.getElementById("googleMap"),mapProp); google.maps.event.addListener(map, 'click', function(event) { placeMarker(event.latLng); }); } function placeMarker(location) { var marker = new google.maps.Marker({ position: location, map: map, }); var infowindow = new google.maps.InfoWindow({ content: 'Latitude: ' + location.lat() + '<br>Longitude: ' + location.lng() }); infowindow.open(map,marker); } google.maps.event.addDomListener(window, 'load', initialize); </script> </head> <body> <div id="googleMap" style="width:500px;height:380px;"></div> </body> </html>