Google Maps API V3 for ASP.NET
Google Maps API V3 for ASP.NET
Introduction
Google Maps provides a flexible way to integrate maps to provide directions, location information, and any other kind of stuff provided by the Google Maps API in your web application. Although there are some articles in CP explaining about maps, in my article I am going to provide information about the latest Google Maps API V3 version. In this article, we will see some of the common techniques that are used with Google Maps. In order to work with the code sample explained below, you need to have some basic knowledge about JavaScript and C#.
In the earlier versions of the Google Maps API, as a developer we need to register the web application with Google and we were supposed to get an API key. However with the release of the new version, key registration has been eliminated for a few days for now, but recently, Google has come up with some kind of traffic limitations and we are supposed to register the application with an API Key. Now we will start our work and create a simple Google Maps map that can be integrated into our site. The following script is used to connect to the Google Maps API:
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false">
</script>
In order to create a simple Google Map map, you can use the following JavaScript code:
function InitializeMap()
{
var latlng = new google.maps.LatLng(-34.397, 150.644);
var myOptions = {
zoom: 8,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map"), myOptions);
}
window.onload = InitializeMap;
 |
| Add caption |
Google Maps Options
In the above example, we used the
Map class which takes options and an HTML ID as parameters. Now moving further, we will look at the map options:function initialize() {
var latlng = new google.maps.LatLng(-34.397, 150.644);
var options =
{
zoom: 3,
center: new google.maps.LatLng(37.09, -95.71),
mapTypeId: google.maps.MapTypeId.ROADMAP,
mapTypeControl: true,
mapTypeControlOptions:
{
style: google.maps.MapTypeControlStyle.DROPDOWN_MENU,
poistion: google.maps.ControlPosition.TOP_RIGHT,
mapTypeIds: [google.maps.MapTypeId.ROADMAP,
google.maps.MapTypeId.TERRAIN,
google.maps.MapTypeId.HYBRID,
google.maps.MapTypeId.SATELLITE]
},
navigationControl: true,
navigationControlOptions:
{
style: google.maps.NavigationControlStyle.ZOOM_PAN
},
scaleControl: true,
disableDoubleClickZoom: true,
draggable: false,
streetViewControl: true,
draggableCursor: 'move'
};
var map = new google.maps.Map(document.getElementById("map"), options);
}
window.onload = initialize;
Map Marker The Marker class provides you with an option to display a marker to the user for a given location. Use of the marker is a very general task that we will use often in our application. The following example shows you how to create a simple marker.
var marker = new google.maps.Marker
(
{
position: new google.maps.LatLng(-34.397, 150.644),
map: map,
title: 'Click me'
}
);
Info Window
With the marker displayed on the map, you create an
onclick event which provides the user with a popup window showing the information about the place. You can create an info window as shown below:
Collapse | Copy Codevar infowindow = new google.maps.InfoWindow({
content: 'Location info:
Country Name:
LatLng:'
});
google.maps.event.addListener(marker, 'click', function () {
// Calling the open method of the infoWindow
infowindow.open(map, marker);
});
Combining them:
Collapse | Copy Codevar map;
function initialize() {
var latlng = new google.maps.LatLng(-34.397, 150.644);
var myOptions = {
zoom: 8,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map"), myOptions);
var marker = new google.maps.Marker
(
{
position: new google.maps.LatLng(-34.397, 150.644),
map: map,
title: 'Click me'
}
);
var infowindow = new google.maps.InfoWindow({
content: 'Location info:<br/>Country Name:<br/>LatLng:'
});
google.maps.event.addListener(marker, 'click', function () {
// Calling the open method of the infoWindow
infowindow.open(map, marker);
});
}
window.onload = initialize;
With this complete, you are going to create a map and then locate the region of the user, load the map with a marker and the info window.
Multiple Markers
In some cases, if you want to handle multiple markers, you achieve this like the following:
function markicons() {
InitializeMap();
var ltlng = [];
ltlng.push(new google.maps.LatLng(17.22, 78.28));
ltlng.push(new google.maps.LatLng(13.5, 79.2));
ltlng.push(new google.maps.LatLng(15.24, 77.16));
map.setCenter(ltlng[0]);
for (var i = 0; i <= ltlng.length; i++) {
marker = new google.maps.Marker({
map: map,
position: ltlng[i]
});
(function (i, marker) {
google.maps.event.addListener(marker, 'click', function () {
if (!infowindow) {
infowindow = new google.maps.InfoWindow();
}
infowindow.setContent("Message" + i);
infowindow.open(map, marker);
});
})(i, marker);
}
}
Directions
One of the most useful features of the Google Maps API is it can be used to provide directions for any given location(s). The following code is used to accomplish this task
var directionsDisplay;
var directionsService = new google.maps.DirectionsService();
function InitializeMap() {
directionsDisplay = new google.maps.DirectionsRenderer();
var latlng = new google.maps.LatLng(-34.397, 150.644);
var myOptions =
{
zoom: 8,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map"), myOptions);
directionsDisplay.setMap(map);
directionsDisplay.setPanel(document.getElementById('directionpanel'));
var control = document.getElementById('control');
control.style.display = 'block';
}
function calcRoute() {
var start = document.getElementById('startvalue').value;
var end = document.getElementById('endvalue').value;
var request = {
origin: start,
destination: end,
travelMode: google.maps.DirectionsTravelMode.DRIVING
};
directionsService.route(request, function (response, status) {
if (status == google.maps.DirectionsStatus.OK) {
directionsDisplay.setDirections(response);
}
});
}
function Button1_onclick() {
calcRoute();
}
window.onload = InitializeMap;
Comments
Post a Comment