Reimers.dk

I just wanted to share my VB.NET example to help others out. - Please do the same and feel free to comment on better ways of doing things.

Imports System.Web.Configuration
Imports System.Data.SqlClient
Imports System.Data
Imports Reimers.WebControls
Imports Reimers.Map

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

Map.GoogleKey = WebConfigurationManager.AppSettings("MapKey").ToString

If Not Page.IsPostBack Then
 
  Map.Center = New GoogleLatLng(42.562539, -83.148805)
  Map.Zoom = 15
  Map.Controls.Add(New Reimers.Map.Controls.GoogleSmallMapTypeControl("smc"))
  Map.Controls.Add(New Reimers.Map.Controls.GoogleSmallMapControl("sc"))

End If

'Handelers ********************

AddHandler Sidebar.Click, AddressOf Sidebar_Click

AddHandler Sidebar.Click, AddressOf Sidebar_Click

AddHandler Map.OverlayClick, AddressOf Me.Map_MarkerClick

'Handelers ********************

Sidebar.AlternatingItemStyle.BackColor = System.Drawing.Color.Blue

Sidebar.Overlays = Map.Overlays

End Sub

---

Protected Sub ListBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged

Dim UserName = HiddenField1.Value

Dim TourString As String = "SELECT dbo.tblDestinations.*, tblAddress.* FROM dbo.tblDestinations INNER JOIN tblAddress ON dbo.tblDestinations.DestinationID = tblAddress.DestinationID Where TourID= '" & ListBox1.SelectedValue & "'"

Dim con1 As String = WebConfigurationManager.ConnectionStrings("ConnectionStringTour").ConnectionString()

Dim Tours As New _

System.Data.SqlClient.SqlDataAdapter(TourString, con1)

Dim dst1 As New System.Data.DataSet()

Tours.Fill(dst1, "tblDestinations")

Dim menuFile As String

menuFile = ""

Dim lat As String

Dim lng As String

Dim address As String

Dim city As String

Dim state As String

Dim zip As String

Dim tele As String

Dim name As String

Dim website As String

Dim logo As String

Dim MyOption As New Reimers.Map.GoogleMarkerOptions

Dim Baloon As String

Dim destinationID As String

Dim ic1 As New GoogleIcon("custom", "http://www.virtualeyes.net/royaloakchamber/icons/ATM.png", New GoogleSize(25, 30), New GooglePoint(16, 16), New GooglePoint(16, 16))

Map.Icons.Add(ic1)

 

For Each masterRow As System.Data.DataRow In dst1.Tables("tblDestinations").Rows()

destinationID = masterRow("DestinationID").ToString()

lat = masterRow("Latitude").ToString()

lng = masterRow("Longitude").ToString()

address = masterRow("Address1").ToString()

city = masterRow("City").ToString()

state = masterRow("State").ToString()

zip = masterRow("Zip").ToString()

tele = masterRow("Phone").ToString()

name = masterRow("DestinationName").ToString()

website = masterRow("website").ToString()

logo = masterRow("Logo").ToString()

Baloon = "<table cellpadding=5 style=width: 356px; position: static; height: 68px><tr><td align=left rowspan=2 valign=middle><img src=" & logo & " style=width: 88px; position: static; height: 90px /></td><td align=left rowspan=2 style=width: 353px valign=middle><strong>" & name & "<br /></strong>" & address & "<br />" & tele & "<br /><a href=http://" & website & " target=_blank >More Info </a><br /></td></tr><tr></tr></table>"

Dim DestEvent As New Reimers.Map.GoogleMarkerOptions

DestEvent.Clickable = True

DestEvent.Title = masterRow("DestinationName").ToString()

Dim MyMarker = New Reimers.Map.GoogleMarker(name, lat, lng, New GoogleMarkerOptions(ic1))

MyMarker.MarkerText = Baloon

Map.Overlays.Add(MyMarker)

Next

Map.PostRenderScript = Map.ZoomToBounds(Map.Overlays.Bounds)

End Sub

---

Protected Sub Map_MarkerClick(ByVal Map As Reimers.Map.GoogleMap, ByVal Marker As GoogleOverlay, ByRef MapCommand As String)

If TypeOf Marker Is GoogleMarker Then

Dim m As GoogleMarker = CType(Marker, GoogleMarker)

MapCommand = m.OpenInfoWindowHTML(Map, "<div>" + m.MarkerText + "</div>")

Else

End If

End Sub

---

Protected Sub Map_Click(ByVal Map As Reimers.Map.GoogleMap, ByVal Point As GoogleLatLng, ByRef MapCommand As String)

MapCommand = Map.OpenInfoWindowHTML(Point, "Lat: " + Point.Latitude.ToString + "<br />Lng: " + Point.Longitude.ToString)

End Sub

---

Function ClientGeocoder1_ClientGeocoded(ByVal Position As Reimers.Map.GoogleLatLng, ByVal IP As String) As String

Dim l As Reimers.Map.Geocoding.Location = Reimers.Map.Geocoding.GoogleGeocoder.ReverseGeocode(Position)

Dim gm As GoogleMarker = New GoogleMarker(DateTime.Now.Millisecond.ToString, l.Point)

gm.MarkerText = String.Format("<p><strong>Nearest Location</strong></p><p>{0}, {1}</p>", l.Address.City, l.Address.Country)

gm.ClientSideHandlers.OnClick = gm.OpenInfoWindowHTML(Map, gm.MarkerText)

Return Map.AddOverlay(gm) + Map.CenterAndZoom(Position, 8) + Map.OpenInfoWindowHTML(Position, String.Format("Your IP address ({0}) is registered here.", IP))

End Function

---

Function Sidebar_MouseOut(ByVal Item As GoogleOverlay) As String

Return Map.CloseInfoWindow

End Function

---

Function Sidebar_Click(ByVal Item As GoogleOverlay) As String

If TypeOf Item Is GoogleMarker Then

Dim m As GoogleMarker = CType(Item, GoogleMarker)

Return m.OpenInfoWindowHTML(Map, m.MarkerText)

Else

Return Nothing

End If

End Function

Thanks for putting up an example that people can learn from (and writing it in VB.NET is nice since I do all my examples in C# which may be difficult for some).

I have a few comments on your code, which are not serious but just to make your code more clean.

Firstly you seem to create the Sidebar click handler twice - oversight?

The second comment is about your indexchanged handler. I would suggest that you clear the Overlays collection before feeding new user values into it. The contents of the Overlays collection are persisted through postbacks and so if the user makes several choices his map will fill up quickly with old data.

Furthermore I would suggest that you use SqlCommands and parameters in your search query. In theory someone could inject an item in your dropdown list with some nasty SQL code as the value thereby ruining your database.

Again on the data retrieval I would suggest you use either an SqlDataReader to get your data. There is no need to use the SqlDataAdapter since you are not going to update the data in the database later. If you do find it easier to use the SqlDataAdapter then I would suggest you restrict yourself to filling only a DataTable. The DataSet is in fact only a superfluous shell.

 Since you are using the SqlDataAdapter you should have a strongly typed DataTable, which means you can cast your values directly into the proper type. I'm thinking about the Latitude and Longitude values which I'm supposing are stored as numeric values in the database. It's one of the things that is easily overlooked when not using Option Strict, but can improve performance.

Again, thanks for posting the example and I encourage everyone to share more of their map ideas. Also feel free to post a link where people can see your page.

Will it be possible for you to post an sample application??

Dim MyMarker = New Reimers.Map.GoogleMarker(name, lat, lng, New GoogleMarkerOptions(ic1))

 

Surely everytime a loop occurs, mymarker would need to be called something else. You'd have to specify an array of markers possibly?

Ignore that last comment. The column did not have the identity property on.

Hey yall, I was curious about something. I am working with the OnZoomChanged and OnMoveEnd events. I am attempting to requery the DB and pull new results based on the bounds of the viewport. I am successful at rebinding the data and setting up the new markers. However the map & markers stay the same until I refresh the page or it posts back from another function on the page. Am I missing a property or method to refresh the markers on the page after I 'rebind' the control? Any help would be appreciated.

 

Thanks

Mike

It sounds like you are not passing any commands back to the map. What you need to do is pass back the commands you want to execute to the MapCommand property of the event args. In your case you would probably want to clear the map and then redraw the new markers:

StringBuilder addAllOverlays = new StringBuilder();

foreach(GoogleMarker mrk in markersToAdd){ addAllOverlays.Append(e.Map.AddOverlay(mrk)); } 

e.MapCommand = e.Map.ClearOverlays() + addAllOverlays.ToString();

That did the trick, I am thankful for your help as I get to know the control!

Another quick question, what kind of object is "markersToAdd" - I created a function that would return a  GoogleOverlayCollection and I am looping over it and adding them like your previous post. I have lost the ability to click and show the info window however. Seems like that error is based on the overlay being "Undefined' - did I do something wrong? My thanks in advance

Hi,

Do you have this in a downloadable format?  When I copy and paste, I get a lot of errors.

Jim

Dear All,

 

 

       I want to overlay existing polygon layers(tables) on gmap.I have about 100 tables or layers which are stored in PostgreSQL/PostGIS .I want to populates those layers on gmap.is it possible.If it is please guide me how to overlay..

 

 I am waiting for your great response.

 

Thanks and Regards,

 

Venkat

You will need to write some code that loops through your dataset and transfers the points to a GooglePolygon. After that it's just a question of adding the polygon as an overlay.