# GoogleMap Overlay **URL:** \ **Category:** WinForms\ **Created:** [September 21, 2011, 7:00am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795 "2011-09-21T07:00:40Z")\ **Posts on this page:** 20\ **Page:** 1

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [September 21, 2011, 7:00am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/1 "2011-09-21T07:00:40Z")

Dear All, I am trying to use google map for my desktop application. For this I have written code like below: WinformsMap1.MapUnit = GeographyUnit.Meter Dim googleMapsOverlay As GoogleMapsOverlay = New GoogleMapsOverlay() WinformsMap1.Overlays.Add(googleMapsOverlay) Dim proj4 As Proj4Projection = New Proj4Projection() proj4.InternalProjectionParametersString = Proj4Projection.GetEpsgParametersString(4326)proj4.ExternalProjectionParametersString = Proj4Projection.GetGoogleMapParametersString() Dim fileName As String = "D:\MapTestFile\New Folder\upw vector\0201\_01.tab" Dim layer As TabFeatureLayer = New TabFeatureLayer(fileName, TabFileReadWriteMode.ReadWrite) layer.Name = "0201\_01" layer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle = PointStyles.CreateSimplePointStyle(PointSymbolType.Circle, GeoColor.StandardColors.Red, GeoColor.StandardColors.Black, 9) layer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20 TabFeatureLayer.BuildIndexFile(fileName) layer.FeatureSource.Projection = proj4 Dim staticOverlay As LayerOverlay = New LayerOverlay() staticOverlay.Layers.Add("tabFileLayer", layer) WinformsMap1.Overlays.Add(staticOverlay) layer.Open() WinformsMap1.CurrentExtent = layer.GetBoundingBox() layer.Close() WinformsMap1.MaximumScale = Double.MaxValue WinformsMap1.MinimumScale = 200 WinformsMap1.Refresh() Its Showing the google map and on screen the area is showing, but not showing data for my Tab file. Is the above method is right or wrong? Please suggest. Regards Sanjay ---

**Author:** ![Gary2](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/g/49beb7/32.png) [@Gary2](https://community.thinkgeo.com/u/Gary2)\ **Post date:** [September 21, 2011, 9:26am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/2 "2011-09-21T09:26:39Z")

Sanjay, Thank you for your post, your sample code looks like everything is OK, the problem maybe is caused by wrong style, does the tab file all contains point? Could you please try to add linestyle and areastyle and have an other try? Regards, Gary ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [September 22, 2011, 12:13am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/3 "2011-09-22T00:13:21Z")

Dear Gary, Thanks for reply, Actually the tab file is based on point based style and it is working with map control, but it is not showing on google map. I have also added all style as you have suggest, but result is same. Dim customLineStyle As Style = New LineStyle(New GeoPen(GeoColor.SimpleColors.Black, 1)) Dim customAreaStyle As Style = New AreaStyle(New GeoPen(GeoColor.SimpleColors.Black, 1)) Dim customPointStyle As Style = New PointStyle(PointSymbolType.Star, New GeoSolidBrush(GeoColor.SimpleColors.LightGreen), 10) Dim customTextStyle As Style = New TextStyle layer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add(customAreaStyle) layer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add(customPointStyle)layer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add(customLineStyle)layer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add(customTextStyle) So, now what we should do. Is the projection is right? Because the google map map unit is Meter and the tab file is LAT LONG (Decimal Degree) based. Regards Sanjay ---

**Author:** ![Gary2](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/g/49beb7/32.png) [@Gary2](https://community.thinkgeo.com/u/Gary2)\ **Post date:** [September 23, 2011, 12:06pm UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/4 "2011-09-23T12:06:34Z")

Sanjay, Sorry I made a wrong conclusion yesterday. I have more test and I can't reproduce it. Please try the code below: ` private void LoadTabFileFeatureLayer_Load(object sender, EventArgs e) { //winformsMap1.MapUnit = GeographyUnit.DecimalDegree; winformsMap1.ThreadingMode = MapThreadingMode.SingleThreaded; //WorldMapKitWmsDesktopOverlay worldMapKitDesktopOverlay = new WorldMapKitWmsDesktopOverlay(); //winformsMap1.Overlays.Add(worldMapKitDesktopOverlay); //winformsMap1.CurrentExtent = new RectangleShape(-96.51477, 30.759543, -94.355788, 28.910652); winformsMap1.BackgroundOverlay.BackgroundBrush = new GeoSolidBrush(GeoColor.GeographicColors.ShallowOcean); winformsMap1.MapUnit = GeographyUnit.Meter; GoogleMapsOverlay googleMapsOverlay = new GoogleMapsOverlay(); winformsMap1.Overlays.Add(googleMapsOverlay); Proj4Projection proj4 = new Proj4Projection(); proj4.InternalProjectionParametersString = Proj4Projection.GetEpsgParametersString(4326); proj4.ExternalProjectionParametersString = Proj4Projection.GetGoogleMapParametersString(); TabFeatureLayer worldLayer = new TabFeatureLayer(@"..\..\SampleData\Data\HoustonMuniBdySamp_Boundary.TAB"); worldLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = AreaStyles.CreateSimpleAreaStyle(GeoColor.FromArgb(100, GeoColor.SimpleColors.Green), GeoColor.SimpleColors.Green); worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20; worldLayer.FeatureSource.Projection = proj4; LayerOverlay staticOverlay = new LayerOverlay(); staticOverlay.Layers.Add("WorldLayer", worldLayer); winformsMap1.Overlays.Add(staticOverlay); worldLayer.Open(); winformsMap1.CurrentExtent = worldLayer.GetBoundingBox(); worldLayer.Close(); winformsMap1.MaximumScale = Double.MaxValue; winformsMap1.MinimumScale = 200; winformsMap1.Refresh(); }` Can you test your tab file, is it work fine without googleoverlay? Regards, Gary ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [September 24, 2011, 4:05am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/5 "2011-09-24T04:05:13Z")

Dear Gary, Thanks for reply, Now it is working, but I am getting some other logical issue, that why earlier it was not working. I am briefing here- 1) First I have taken googlemaplayer and added on WinformsMap1.Overlays.Add(googleMapLayer) 2) Now I open tab file and try to adding TabFeatureLayer:- I am trying to add like a) Dim staticOverlay As LayerOverlay = New LayerOverlay() staticOverlay.Layers.Add(“WorldLayer”, layer) 'layer is tabfeaturelayer WinformsMap1.Overlays.Add(staticOverlay) Its showing map on googleoverlay b) WinformsMap1.Overlays(0).Lock.EnterWriteLock() Try DirectCast(WinformsMap1.Overlays(0), LayerOverlay).Layers.Add(layerName, layer) Finally WinformsMap1.Overlays(0).Lock.ExitWriteLock() End Try Its not working. Is there any difference in method a and method b? Because in both method I have written LayerOverlay then why not it is working with second method. I need to resolve first method into second one, because second method is applyed in my whole application. Please suggest. Regards Sanjay ---

**Author:** ![Gary2](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/g/49beb7/32.png) [@Gary2](https://community.thinkgeo.com/u/Gary2)\ **Post date:** [September 26, 2011, 1:48pm UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/6 "2011-09-26T13:48:29Z")

Sanjay, In the method b, if you use WinformsMap1.Overlays(0), that’s not a LayerOverlay, it’s our default background overlay, so this will cause problem. Please use the method a as we recommend. Regards, Gary ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [September 29, 2011, 3:16am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/7 "2011-09-29T03:16:18Z")

Dear Gary, Thanks for reply. Please understand my requirement. previously I made an application without support of google map. For that on form load I set the following: WinformsMap1.MapUnit = GeographyUnit.DecimalDegree WinformsMap1.Overlays.Add(New LayerOverlay()). Now I added multiple tab file and all the tab file is added with : DirectCast(WinformsMap1.Overlays(0), LayerOverlay).Layers.Add(layerName, layer) here layername is name of layer and layer is TabFutureLayer, also there are many activity doing with application and when required I am able to add,remove and find the layer with help of Directcast. It all working for me. Now I want to add a feature of googlemap for this I added a button to set the google map layer with following code WinformsMap1.MapUnit = GeographyUnit.Meter Dim googleMapLayer As GoogleMapsOverlay = New GoogleMapsOverlay() WinformsMap1.Overlays.Add(googleMapLayer) and at times of Tab file loading I am checking is it google map or not, if it is google map I am setting the projection Dim proj4 As Proj4Projection = New Proj4Projection() proj4.InternalProjectionParametersString = Proj4Projection.GetEpsgParametersString(4326) proj4.ExternalProjectionParametersString = Proj4Projection.GetGoogleMapParametersString() layer.FeatureSource.Projection = proj4 and at last the same way try to add layer on google map. My google map is viewing but not the tab file. Now I want to work with same application with googlemap layer, so that I tried to add DirectCast(WinformsMap1.Overlays(0), LayerOverlay).Layers.Add(layerName, layer) for the same. so, 1) As I mention on form load I have added LayerOverlay in WinformsMap1.Overlay, so it should be LayerOverlay. 2) If WinformsMap1.Overlays(0) is background overlay, how and what we should change in the statement, so that it works in both case as LayerOverlay. Please suggest Regards Sanjay ---

**Author:** ![ThinkGeo](https://community.thinkgeo.com/user_avatar/community.thinkgeo.com/thinkgeo/32/25029_2.png) [@ThinkGeo](https://community.thinkgeo.com/u/ThinkGeo)\ **Post date:** [September 30, 2011, 10:28am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/8 "2011-09-30T10:28:25Z")

Sanjay, Sorry for the inconvenience, I think your real problem is that the code : DirectCast(WinformsMap1.Overlays(0), LayerOverlay).Layers.Add(layerName, layer) You said it is not working correctly, according to my tests I cannot reproduce your problem exactly, can you arrange a simple sample to us so that we can fix your problem exactly? Thanks, Scott, ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [October 3, 2011, 1:37am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/9 "2011-10-03T01:37:55Z")

Dear Scott, Thanks for reply. I have uploaded a zip file for your reference. You can find this in my ticket no. 3370. Please recreate the problem and suggest me. Regards Sanjay ---

**Author:** ![Gary2](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/g/49beb7/32.png) [@Gary2](https://community.thinkgeo.com/u/Gary2)\ **Post date:** [October 3, 2011, 11:04am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/10 "2011-10-03T11:04:21Z")

Hello Sanjay, Thank you for your sample, we got it, and will let you know the answer as soon as possible. Regards, Gary ---

**Author:** ![Gary2](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/g/49beb7/32.png) [@Gary2](https://community.thinkgeo.com/u/Gary2)\ **Post date:** [October 6, 2011, 8:03am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/11 "2011-10-06T08:03:11Z")

Hello Sanjay, Thank you for your sample code, with it, we can find the root cause. The problem is map overlay draw order. You have added the LayerOverlay at the beginning, then add the GoogleOverlay, that will let the LayerOverlay draw first, GoogleOverlay after it. There are two solutions to resolved it: 1. Don’t use the LayerOverlay you have added. try to add new LayerOverlay every time you add tabFeatureLayer. LayerOverlay staticOverlay = new LayerOverlay(); staticOverlay.Layers.Add(“WorldLayer”, worldLayer); winformsMap1.Overlays.Add(staticOverlay); 2. Use the first LayerOverlay but move the GoogleOverlay to the bottom to make sure draw it first. WinformsMap1.Overlays.MoveDown(1) but please notice change your code WinformsMap1.Overlays(0) to WinformsMap1.Overlays(“layerOverlay”) to get your layerOverlay, otherwise it will throw exception. Any more questions please feel free to let us know. Regards, Gary ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [November 4, 2011, 6:35am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/12 "2011-11-04T06:35:09Z")

Dear Gary, Thanks for reply, and sorry from my side in delay in response, actually I was busy in some other project. I have changed my code as per your suggestion and at first glance it is working, but some concern is below: 1) Some tab file which is working without googlemap, those file not working with googlemap, any reason you can specify. 2) Some times tab file loaded, but its not showing on google map and also the color of google map disappear. Can you suggest something. Hoping for your response. Regards Sanjay ---

**Author:** ![Val](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/v/e56c9b/32.png) [@Val](https://community.thinkgeo.com/u/Val)\ **Post date:** [November 4, 2011, 9:17am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/13 "2011-11-04T09:17:14Z")

Sanjay, Before you get a more detailed answer from your support guy, let me tell you what I think the problem is by reading your descriptions. I think that you have a projection issue. I think that your tab file is in another projection which means that it is not going to show up in line with GoogleMap. I hope that I gave you some directions about what could be the problem in your case before you get some more specific help from Gary. Thank you. ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [November 5, 2011, 12:11am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/14 "2011-11-05T00:11:46Z")

Dear Val, Thank you for reply, Actually, when I am loading my tab file, following code is written Private Sub AddTabFeatureLayers(ByVal fileNames As IEnumerable(Of String)) For Each fileName As String In fileNames Try Dim layerName As String = System.IO.Path.GetFileNameWithoutExtension(fileName) If Not DirectCast(WinformsMap1.Overlays(“layerOverlay”), LayerOverlay).Layers.Contains(layerName) Then Dim layer As TabFeatureLayer = New TabFeatureLayer(fileName, TabFileReadWriteMode.ReadWrite) layer.Name = layerName ExplorerHelper.SetStyleByWellKnownType(layer) layer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20 'layer.RequireIndex = False TabFeatureLayer.BuildIndexFile(fileName) '---------------- Dim boundingBox As RectangleShape = Nothing Process.GetCurrentProcess().ProcessorAffinity = CType(1, System.IntPtr) If layer.HasBoundingBox Then If Not layer.IsOpen Then layer.Open() 'Dim b As Boolean = layer.FeatureSource.CanExecuteSqlQuery 'Dim dt As DataTable = layer.FeatureSource.ExecuteQuery("Select \* from " & layerName) End If If boundingBox Is Nothing Then boundingBox = layer.GetBoundingBox() Else boundingBox.ExpandToInclude(layer.GetBoundingBox()) End If layer.Close() End If Dim boxArea As String = boundingBox.ToString Dim bArea() As String = Split(boxArea, “,”) Dim xLatCor As Double Dim yLongCor As Double If CDbl(bArea(0)) \<\> 0 Then xLatCor = CDbl(bArea(0)) If xLatCor \< 0 Then xLatCor = CDbl(bArea(2)) End If Else xLatCor = CDbl(bArea(2)) End If If CDbl(bArea(1)) \<\> 0 Then yLongCor = CDbl(bArea(1)) If yLongCor \< 0 Then yLongCor = CDbl(bArea(3)) End If Else yLongCor = CDbl(bArea(3)) End If If Math.Abs(xLatCor) \> -180 And Math.Abs(xLatCor) \< 180 Then 'This is decimal degree map If G\_GoogleLayerSelected = True Then Dim proj4 As Proj4Projection = New Proj4Projection() proj4.InternalProjectionParametersString = Proj4Projection.GetEpsgParametersString(4326) proj4.ExternalProjectionParametersString = Proj4Projection.GetGoogleMapParametersString() layer.FeatureSource.Projection = proj4 End If Else 'This is meter map Dim proj4 As ManagedProj4Projection = New ManagedProj4Projection proj4.InternalProjectionParametersString = ManagedProj4Projection.GetEpsgParametersString(32643) proj4.ExternalProjectionParametersString = ManagedProj4Projection.GetEpsgParametersString(4326) layer.FeatureSource.Projection = proj4 End If layer.DrawingQuality = DrawingQuality.CanvasSettings WinformsMap1.Overlays(“layerOverlay”).Lock.EnterWriteLock() Try DirectCast(WinformsMap1.Overlays(“layerOverlay”), LayerOverlay).Layers.Add(layerName, layer) Finally WinformsMap1.Overlays(“layerOverlay”).Lock.ExitWriteLock() End Try SetupThemeItem(layer) addedFiles.Add(fileName) WinformsMap1.CenterAt(New PointShape(xLatCor, yLongCor)) End If Catch fle As FileLoadException RemoveFeaturefile(DirectCast(fle.InnerException, FileNotFoundException)) Catch ex As Exception MessageBox.Show(ex.Message, ex.[GetType]().ToString(), MessageBoxButtons.OK, MessageBoxIcon.[Error], MessageBoxDefaultButton.Button1, DirectCast(0, MessageBoxOptions)) End Try Next End Sub In my point of view, my all .TAB file is decimal degree. So, please give some more help. Regards Sanjay ---

**Author:** ![Val](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/v/e56c9b/32.png) [@Val](https://community.thinkgeo.com/u/Val)\ **Post date:** [November 7, 2011, 8:10am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/15 "2011-11-07T08:10:06Z")

Sanjay, We would need to see your tab file. It is difficult to see what is happening with only your code without being able to run it. You can attach your tab file to this post or, if you feel more confortable, you can send it to [support@thinkgeo.com](mailto:support@thinkgeo.com). We are waiting for your response. Thank you. ---

**Author:** ![Val](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/v/e56c9b/32.png) [@Val](https://community.thinkgeo.com/u/Val)\ **Post date:** [November 14, 2011, 10:29am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/16 "2011-11-14T10:29:32Z")

Sanjay, Can you let us know in this post if you sent your tab file to [support@thinkgeo.com](mailto:support@thinkgeo.com) or if you still need help for this? Thank you. ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [November 14, 2011, 11:35pm UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/17 "2011-11-14T23:35:55Z")

Dear Val, Sorry for delay, because I was out of station. So sorry once again. I have sended my zipped file on [support@thinkgeo.com](mailto:support@thinkgeo.com). In the zipped file there was code as well as four tab file and the status of all tab file is like below 1) 0201\_01.tab - this file is working properly in both mode. In Normal as well as google. 2) AZX0325\_1.tab - this file is working in Normal mode, although you will not see on screen, but when you click in full extent button, it will show on screen. But it will not show on google map. 3) Dasa0325\_01.tab - the exception coming and message is "Read and write not equal". This message is coming in both mode. What is the meaning? 4) bulend010.tab - this file is working in Normal mode, although you will not see on screen, but when you click in full extent button, it will show on screen. But when you try to open this file on google map, it gives exception "Parameter is not valid" Please check the tab file and advice me the best way to deal with this. Regards Sanjay ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [November 16, 2011, 2:25am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/18 "2011-11-16T02:25:59Z")

Dear val, Can I upload my zipped file with my ticket with 3370 / 4270? Because I got mail from supports, they are not able to download, because my files showing virus. I check my files with Micosoft Security Essentials and its not showing any threat. I also try to upload files with FTP, but I think there is some permission issue. So, if I can send this file with my ticket. Regards Sanjay ---

**Author:** ![Val](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/v/e56c9b/32.png) [@Val](https://community.thinkgeo.com/u/Val)\ **Post date:** [November 16, 2011, 10:41am UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/19 "2011-11-16T10:41:37Z")

Sanjay, Using FTP is our prefered way to receive files. Please, follow exactly the instructions that were sent to you for using our FTP and you should not have any problem. Thank you. ---

**Author:** ![Sanjay](https://community.thinkgeo.com/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@Sanjay](https://community.thinkgeo.com/u/Sanjay)\ **Post date:** [November 16, 2011, 10:57pm UTC](https://community.thinkgeo.com/t/googlemap-overlay/1795/20 "2011-11-16T22:57:46Z")

Dear Val, I have uploaded my .rar file on FTP. I hope you will get soon. Regards Sanjay [Next page](https://community.thinkgeo.com/t/googlemap-overlay/1795.md?page=2)