Introduction:
Here
I will explain how to populate or show or add multiple markers to Google
maps V3 from database in asp.net website using JavaScript or JavaScript populate or Show Google
maps with multiple markers from database in asp.net.
Description:
In
previous article I explained clearly how to add Google map to website in
asp.net,
Add marker to Google map in asp.net
website,
JavaScript Add multiple markers to
google map,
jQuery image slideshow in asp.net, Sitemap navigation control example in
asp.net
and many articles relating to jQuery, JavaScript, asp.net. Now I will explain
how to populate Google maps from database with multiple markers in asp.net website.
Before
add multiple markers to Google map from database we need to get Google
API
key for that please check below url
Once
you got the key create new table in your database like as shown below
Column Name
|
Data Type
|
Allow Nulls
|
Id
|
int(set
identity property=true)
|
No
|
City
|
varchar(50)
|
Yes
|
Latitude
|
numeric(12,6)
|
Yes
|
Longitude
|
numeric(12,6)
|
Yes
|
Description
|
Varchar(250)
|
Yes
|
Once
table creation completed enter some sample data like as shown below
 |
Now
write the following code in your aspx to show multiple markers in Google map from database like
as shown below
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Show/Add multiple markers to Google Maps from database in
asp.net website</title>
<style type="text/css">
html { height: 100% }
body { height: 100%; margin: 0; padding: 0 }
#map_canvas { height: 100% }
</style>
<script type="text/javascript" src = "https://maps.googleapis.com/maps/api/js?key=AIzaSyC6v5-2uaq_wusHDktM9ILcqIrlPtnZgEk&sensor=false">
</script>
<script type="text/javascript">
function initialize() {
var markers = JSON.parse('<%=ConvertDataTabletoString()
%>');
var mapOptions = {
center: new
google.maps.LatLng(markers[0].lat, markers[0].lng),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
// marker:true
};
var infoWindow = new
google.maps.InfoWindow();
var map = new
google.maps.Map(document.getElementById("map_canvas"),
mapOptions);
for (i = 0; i < markers.length; i++) {
var data = markers[i]
var myLatlng = new
google.maps.LatLng(data.lat, data.lng);
var marker = new
google.maps.Marker({
position: myLatlng,
map: map,
title: data.title
});
(function(marker,
data) {
// Attaching a click event to the
current marker
google.maps.event.addListener(marker, "click", function(e)
{
infoWindow.setContent(data.description);
infoWindow.open(map, marker);
});
})(marker, data);
}
}
</script>
</head>
<body onload="initialize()">
<form id="form1"
runat="server">
<div id="map_canvas"
style="width:
500px; height: 400px"></div>
</form>
</body>
</html>
|
If you observe above code in header
section I mentioned multiple latitude and longitudes of different cities and by
default I mentioned one city latitude and longitude by using that default
details we can center the map to near place of other cities based on that other
cities whatever we are going to mark are visible.
In remaining code markers
are used to add marking in google map and infowindow is used to show info of
all the cities based on the description whatever we mentioned in json string.
Now add following
namespaces in code behind
C# Code
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
|
After
that write the following code in code behind
// This method is used to convert
datatable to json string
public string
ConvertDataTabletoString()
{
DataTable dt = new DataTable();
using (SqlConnection
con = new SqlConnection("Data Source=SureshDasari;Initial Catalog=master;Integrated
Security=true"))
{
using (SqlCommand
cmd = new SqlCommand("select
title=City,lat=latitude,lng=longitude,description from LocationDetails",
con))
{
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
List<Dictionary<string, object>>
rows = new List<Dictionary<string,
object>>();
Dictionary<string, object> row;
foreach (DataRow
dr in dt.Rows)
{
row = new Dictionary<string,
object>();
foreach (DataColumn
col in dt.Columns)
{
row.Add(col.ColumnName, dr[col]);
}
rows.Add(row);
}
return serializer.Serialize(rows);
}
}
}
|
VB.NET Code
Imports System.Collections.Generic
Imports System.Data
Imports System.Data.SqlClient
Partial Class
Default3
Inherits System.Web.UI.Page
Protected Sub
Page_Load(ByVal sender As Object, ByVal e As
EventArgs)
End Sub
' This method is used to convert datatable
to json string
Public Function
ConvertDataTabletoString() As String
Dim dt As New DataTable()
Using con As New SqlConnection("Data
Source=SureshDasari;Initial Catalog=master;Integrated Security=true")
Using cmd As New SqlCommand("select
title=City,lat=latitude,lng=longitude,description from LocationDetails",
con)
con.Open()
Dim da As New SqlDataAdapter(cmd)
da.Fill(dt)
Dim serializer As New
System.Web.Script.Serialization.JavaScriptSerializer()
Dim rows As New List(Of
Dictionary(Of String,
Object))()
Dim row As Dictionary(Of String, Object)
For Each dr As DataRow In
dt.Rows
row = New
Dictionary(Of String,
Object)()
For Each col As DataColumn In
dt.Columns
row.Add(col.ColumnName, dr(col))
Next
rows.Add(row)
Next
Return serializer.Serialize(rows)
End Using
End Using
End Function
End Class
|
Demo
 |
Download
Sample Code Attached
|
If you enjoyed this post, please support the blog below. It's FREE! Get the latest Asp.net, C#.net, VB.NET, jQuery, Plugins & Code Snippets for FREE by subscribing to our Facebook, Twitter, RSS feed, or by email. |
|||
Subscribe by RSS
Subscribe by Email
|
|||
4 comments :
Finally some good explanation and solution :) Thank you very much :)
it is working but tittle no showing on Map
i have a error in ConvertDataTabletoString() part to throw not all code paths return a vlue how to i solve it
SUPERBBBB SURESH....!! THANK U SO MUCH
Note: Only a member of this blog may post a comment.