Click here to Skip to main content
15,120,078 members
Articles / Desktop Programming / Windows Forms
Posted 18 Jan 2009


506 bookmarked

GMap.NET - Great Maps for Windows Forms and Presentation

Rate me:
Please Sign up or sign in to vote.
4.80/5 (132 votes)
16 Apr 2013MIT1 min read
GMap.NET is a powerful, free, cross platform, Open Source .NET control. It enables the use of routing, geocoding, and maps from Google, Yahoo!, OpenStreet in Windows Forms and Presentation, and supports caching!



Google Maps are cool, yeah? But it's useful only in the browser, and is insufficient for real time tracking. It also does not have cache so Google servers are overloaded. This control removes all these deficiencies! It also gives the .NET developer unlimited ability to extend it!

GMap.NET is great and Powerful, Free, cross platform, open source .NET control. Enable use routing, geocoding, directions and maps from Google, Yahoo!, Bing, OpenStreetMap, ArcGIS, Pergo, SigPac, Yandex,,,, NearMap, OviMap, CloudMade, WikiMapia, MapQuest in Windows Forms & Presentation, supports caching and runs on windows mobile! 


The basic idea is simple: get the required data from Google/etc., cache it, and use it. Fast, simple, and practical.

Using the Code

It's more than easy. GMap.NET.dll and GMap.NET.WindowsForms.dll contain the user control. Add it to your project and simply use it.

Here are the basic control initial options: 

public MainForm()


   System.Net.IPHostEntry e =
   MainMap.Manager.Mode = AccessMode.CacheOnly;
   MessageBox.Show("No internet connection avaible, going to CacheOnly mode.", 
         "GMap.NET - Demo.WindowsForms", MessageBoxButtons.OK,

// config map
MainMap.MapProvider = GMapProviders.OpenStreetMap;
MainMap.Position = new PointLatLng(54.6961334816182, 25.2985095977783);
MainMap.MinZoom = 0;
MainMap.MaxZoom = 24;
MainMap.Zoom = 9;

// add your custom map db provider
//GMap.NET.CacheProviders.MySQLPureImageCache ch = new GMap.NET.CacheProviders.MySQLPureImageCache();
//ch.ConnectionString = @"server=sql2008;User Id=trolis;Persist Security Info=True;database=gmapnetcache;password=trolis;";
//MainMap.Manager.SecondaryCache = ch;

// set your proxy here if need
//GMapProvider.WebProxy = new WebProxy("", 8080);
//GMapProvider.WebProxy.Credentials = new NetworkCredential("", "bilgeada");

// map events
   MainMap.OnPositionChanged += new PositionChanged(MainMap_OnPositionChanged);

   MainMap.OnTileLoadStart += new TileLoadStart(MainMap_OnTileLoadStart);
   MainMap.OnTileLoadComplete += new TileLoadComplete(MainMap_OnTileLoadComplete);

   MainMap.OnMapZoomChanged += new MapZoomChanged(MainMap_OnMapZoomChanged);
   MainMap.OnMapTypeChanged += new MapTypeChanged(MainMap_OnMapTypeChanged);

   MainMap.OnMarkerClick += new MarkerClick(MainMap_OnMarkerClick);
   MainMap.OnMarkerEnter += new MarkerEnter(MainMap_OnMarkerEnter);
   MainMap.OnMarkerLeave += new MarkerLeave(MainMap_OnMarkerLeave);

   MainMap.OnPolygonEnter += new PolygonEnter(MainMap_OnPolygonEnter);
   MainMap.OnPolygonLeave += new PolygonLeave(MainMap_OnPolygonLeave);

   MainMap.OnRouteEnter += new RouteEnter(MainMap_OnRouteEnter);
   MainMap.OnRouteLeave += new RouteLeave(MainMap_OnRouteLeave);

   MainMap.Manager.OnTileCacheComplete += new TileCacheComplete(OnTileCacheComplete);
   MainMap.Manager.OnTileCacheStart += new TileCacheStart(OnTileCacheStart);
   MainMap.Manager.OnTileCacheProgress += new TileCacheProgress(OnTileCacheProgress);

As you can see, the control options are quite simple. And there is nothing more to add.

Points of Interest

Well, it was quite cryptic to figure out how Google manages tiles, what coordinate system it uses, the JSON decryption, etc.


Go to the project's CodePlex site to get a running update of any changes or improvements I've made.  


This article, along with any associated source code and files, is licensed under The MIT License


About the Author
Software Developer
Lithuania Lithuania
No Biography provided

Comments and Discussions

Qismet16-May-12 1:16
MemberQismet16-May-12 1:16 
radioman.lt16-May-12 1:20
Memberradioman.lt16-May-12 1:20 
GeneralRe: SOURCE CODE Pin
Qismet16-May-12 1:35
MemberQismet16-May-12 1:35 
QuestionI need to use address instead of lat and lng? Pin
Ben Paxton14-Mar-12 3:06
MemberBen Paxton14-Mar-12 3:06 
AnswerRe: I need to use address instead of lat and lng? Pin
radioman.lt14-Mar-12 4:10
Memberradioman.lt14-Mar-12 4:10 
GeneralRe: I need to use address instead of lat and lng? Pin
Ben Paxton14-Mar-12 5:34
MemberBen Paxton14-Mar-12 5:34 
GeneralRe: I need to use address instead of lat and lng? Pin
radioman.lt14-Mar-12 6:22
Memberradioman.lt14-Mar-12 6:22 
AnswerRe: I need to use address instead of lat and lng? Pin
Dan Randolph27-Apr-17 13:16
MemberDan Randolph27-Apr-17 13:16 
Here is how you do it. I like the Google geocoder for best lookup lat/lon, although it might throw some false positives if it does not have the the "local" name for the street in the database. Tested with this address query example "1600 Pennsylvania Ave NW, Washington, DC" for textBoxGeo.Text.
//Find Location using GMapProvider.GoogleMap
private void btnFind_Click(object sender, RoutedEventArgs e)
  Map searchMap = new Map();
  searchMap.MapProvider = GMapProviders.GoogleMap;
  GeoCoderStatusCode status = searchMap.SetPositionByKeywords(textBoxGeo.Text);
  if (status != GeoCoderStatusCode.G_GEO_SUCCESS)
    MessageBox.Show("Geocoder can't find: '" + textBoxGeo.Text + "', reason: " + status.ToString(), "GMap.NET", MessageBoxButton.OK, MessageBoxImage.Exclamation);
    MainMap.Position = searchMap.Position;
    currentMarker.Position = searchMap.Position;
    textBoxLat.Text = String.Format("{0:f8}", searchMap.Position.Lat);
    textBoxLng.Text = String.Format("{0:f8}", searchMap.Position.Lng);
    //Show found location on map
    MainMap.Position = new PointLatLng(searchMap.Position.Lat, searchMap.Position.Lng);
    MainMap.Zoom = 18.0; //make sure your MaxZoom setting allows this value in <src:Map /> xaml

QuestionSome simple documentation for GMap.Net Pin
smartradio13-Mar-12 3:20
Membersmartradio13-Mar-12 3:20 
QuestionExample don´t working in C# 2008 Pin
smartradio13-Mar-12 3:18
Membersmartradio13-Mar-12 3:18 
AnswerRe: Example don´t working in C# 2008 Pin
radioman.lt13-Mar-12 3:30
Memberradioman.lt13-Mar-12 3:30 
GeneralRe: Example don´t working in C# 2008 Pin
smartradio13-Mar-12 5:16
Membersmartradio13-Mar-12 5:16 
Questionoffline maps Pin
mojimoj29-Feb-12 1:25
Membermojimoj29-Feb-12 1:25 
AnswerRe: offline maps Pin
radioman.lt29-Feb-12 2:44
Memberradioman.lt29-Feb-12 2:44 
Questionnice app Pin
BillW3314-Feb-12 12:22
professionalBillW3314-Feb-12 12:22 
AnswerRe: nice app Pin
radioman.lt14-Feb-12 23:11
Memberradioman.lt14-Feb-12 23:11 
QuestionPb in using GMap contril in C++.NET Pin
gilmegviv31-Jan-12 12:11
Membergilmegviv31-Jan-12 12:11 
AnswerRe: Pb in using GMap contril in C++.NET Pin
radioman.lt31-Jan-12 21:53
Memberradioman.lt31-Jan-12 21:53 
GeneralRe: Pb in using GMap contril in C++.NET Pin
gilmegviv2-Feb-12 10:11
Membergilmegviv2-Feb-12 10:11 
QuestionHow do I load a TMS that was created using maptiler and Geotiff Pin
Andrew Mellon20-Dec-11 13:58
MemberAndrew Mellon20-Dec-11 13:58 
AnswerRe: How do I load a TMS that was created using maptiler and Geotiff Pin
radioman.lt20-Dec-11 21:34
Memberradioman.lt20-Dec-11 21:34 
GeneralRe: How do I load a TMS that was created using maptiler and Geotiff Pin
Andrew Mellon21-Dec-11 10:24
MemberAndrew Mellon21-Dec-11 10:24 
GeneralRe: How do I load a TMS that was created using maptiler and Geotiff Pin
Andrew Mellon22-Dec-11 10:37
MemberAndrew Mellon22-Dec-11 10:37 
GeneralRe: How do I load a TMS that was created using maptiler and Geotiff Pin
radioman.lt22-Dec-11 10:56
Memberradioman.lt22-Dec-11 10:56 
GeneralRe: How do I load a TMS that was created using maptiler and Geotiff Pin
kenzai27-Dec-11 23:12
Memberkenzai27-Dec-11 23:12 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.