topic pan as my graphic tracker symbol moves in ArcObjects SDK Questions

pan as my graphic tracker symbol moves

DarcyHathaway — Wed, 14 Aug 2013 15:45:44 GMT

I need help to make the map pan as my graphic tracker symbol moves based on the GPS feed.
I am using Arc Object 10 with VS.net VB.

Re: pan as my graphic tracker symbol moves

JeffMatson — Wed, 14 Aug 2013 16:45:29 GMT

I need help to make the map pan as my graphic tracker symbol moves based on the GPS feed.
I am using Arc Object 10 with VS.net VB.

The basic method would be to use IActiveView and IEnvelope. Each time your graphic tracker symbol moves, use IEnvelope.CenterAt() and reset your IActiveView.Extent to the updated Envelope, and then refresh.

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Wed, 14 Aug 2013 21:31:19 GMT

The basic method would be to use IActiveView and IEnvelope. Each time your graphic tracker symbol moves, use IEnvelope.CenterAt() and reset your IActiveView.Extent to the updated Envelope, and then refresh.

That will not work because the map refreshes every time the GPS changes this is every half a second. It causes the map to blip and is very ugly, not acceptable.

Re: pan as my graphic tracker symbol moves

JeffMatson — Wed, 14 Aug 2013 21:51:31 GMT

That will not work because the map refreshes every time the GPS changes this is every half a second. It causes the map to blip and is very ugly, not acceptable.

There are many ways to refresh the map without the dreaded "blipping" but it depends on how you are going about things. Maybe if you post some more information or a code sample someone can help.

Re: pan as my graphic tracker symbol moves

LeoDonahue — Wed, 14 Aug 2013 21:51:40 GMT

You could look at: com.esri.arcgis.carto.CenterAndScale

Graphics Tracker should be handling your refresh, right? You are not explicitly calling map.refresh are you?

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Thu, 15 Aug 2013 14:15:30 GMT

Yes, the graphic tracker is handling the refresh for the symbol and it moves perfectly but I need the map to pan as the symbol moves out of view to the user will not have to manually pan while driving.

here is my code.

I have a GPS that is running in the background getting the Lat and Long when it is changing and feeding.
This code below is running on a timer Me.Timer1.Interval = 500 and works great for the graphic tracker.
Sub Lat_Long(ByRef Latcoord As String, ByVal Longcoord As String)

        Dim activeView As IActiveView = TryCast(map, IActiveView)

        If Latcoord <> "" And Longcoord <> "" Then

            m_graphicTracker.Initialize(TryCast(map, IBasicMap))

            Dim gc As IGraphicsContainer
            gc = activeView

            ' Get the spatial reference of the map (UTM)
            Dim sr As ISpatialReference
            sr = activeView.FocusMap.SpatialReference

            '' Create a point and assign the geographic coordinate system (lat/long)
            Dim point As IPoint = New ESRI.ArcGIS.Geometry.Point

            ' Get the geographic coordinate system used by the map's spatial reference (lat/long)
            Dim geoSR As ISpatialReference
            Dim psr As IProjectedCoordinateSystem
            psr = sr
            geoSR = psr.GeographicCoordinateSystem

            point.SpatialReference = geoSR
            ' Give the point coordinates known to exist in the current extent
            point.PutCoords(Longcoord, Latcoord)
            point.Project(sr)

            If PointFirstTime = True Then
                'Get the Graphic Symbol
                Dim gtSymbol As IGraphicTrackerSymbol = m_GTSymbols(2)

                Dim id As Integer = m_graphicTracker.Add(TryCast(point, IGeometry), gtSymbol)

                m_GTGeometries.Add(0, TryCast(point, IGeometry))
                m_graphicTracker.Replace(0, m_GTGeometries(0), m_GTSymbols(2))

            End If

            If m_graphicTracker IsNot Nothing Then
                For i As Integer = 0 To m_graphicTracker.Count - 1
                    Dim id1 As Integer = i
                    If m_GTGeometries.ContainsKey(id1) Then
                        'Dim pnt As IPoint = DirectCast(m_GTGeometries(id), IPoint)
                        Dim pnt As IPoint = point
                        Dim x As Double = pnt.X
                        Dim y As Double = pnt.Y

                        m_graphicTracker.MoveTo(id1, x, y, 0)
                        m_GTGeometries.Remove(id1)
                        Dim point1 As IPoint = New ESRI.ArcGIS.Geometry.Point
                        point1.PutCoords(x, y)
                        m_GTGeometries.Add(id1, point1)

                        Try

                            If activeView Is Nothing Then
                                Return
                            End If

                            Dim screenDisplay As ESRI.ArcGIS.Display.IScreenDisplay = activeView.ScreenDisplay

                            'Here I am trying a couple of ways to get it to pan

                            Dim envelope As ESRI.ArcGIS.Geometry.IEnvelope = activeView.Extent

                            envelope.CenterAt(point1)
                            envelope.Expand(0, 0, True)

                            activeView.Extent = envelope
                            'This causes a blip
                            ' activeView.Refresh()

                            point.PutCoords(SaveLongCoord, SaveLatCoord)
                            point.Project(sr)
                            activeView.CenterAt(point)
                            'This causes a blip
                            'activeView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, TryCast(basemapLayer, Object), Nothing)


                        Catch ex As Exception

                        End Try

                    End If
                Next
            End If

            PointFirstTime = False

        End If

    End Sub

Re: pan as my graphic tracker symbol moves

JeffMatson — Thu, 15 Aug 2013 14:59:27 GMT

You might need to cache your layers (not sure what type of layer 'basemapLayer' is) to avoid the blips.

Also since you have an envelope, pass that into partialRefresh. Lastly you might need to change the draw phase being passed into partialRefresh (you can also combine several draw phases)

Hope that helps

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 14:52:21 GMT

I am creating this in a window application.

I tried activeView.PartialRefresh(esriViewDrawPhase.esriViewBackground, Nothing, envelope) and it is not working.

Re: pan as my graphic tracker symbol moves

LeoDonahue — Fri, 16 Aug 2013 15:39:02 GMT

partial refresh is not working or it is not giving you the effect you wanted?

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 15:42:30 GMT

It is not giving me the effect I want.

I really need the map to pan to the point as the point moves.

Re: pan as my graphic tracker symbol moves

LeoDonahue — Fri, 16 Aug 2013 15:46:42 GMT

Did you try using this class? com.esri.arcgis.carto.CenterAndScale

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 15:53:44 GMT

The class com.esri.arcgis.carto.CenterAndScale looks like it is for Java and I am creating this in a windows PC application.

Re: pan as my graphic tracker symbol moves

LeoDonahue — Fri, 16 Aug 2013 16:01:49 GMT

Oh my mistake.

http://resources.arcgis.com/en/help/arcobjects-net/componenthelp/0012/0012000002sm000000.htm

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 16:14:40 GMT

Yes I have tried that and that is what is causing the blip because of the refresh.

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 19:29:05 GMT

I took a closer look at the CoClasses and Classes that you sent me to look into and I cannot use this because it too is for a web application using a Mapserver and I am creating this application for a windows PC application using a Geo database.

Re: pan as my graphic tracker symbol moves

LeoDonahue — Fri, 16 Aug 2013 19:48:35 GMT

Take a closer look.

Provides access to the Center And Scale Map Area Interface.

Product Availability Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Re: pan as my graphic tracker symbol moves

LeoDonahue — Fri, 16 Aug 2013 19:59:15 GMT

Sorry Darcy, that example uses MapServer, why? I have no idea. But it will work with desktop.

And, I thought you said that this solution causes a blip anyway?

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 20:29:52 GMT

Well I had to take a closer look and see if I was missing something.

I am not using desktop either, I am using Visual Studio .net.

Do you have an example?

Re: pan as my graphic tracker symbol moves

LeoDonahue — Fri, 16 Aug 2013 20:33:51 GMT

So.... that leaves us with ArcGIS Engine? And that class is still supported there also.

Re: pan as my graphic tracker symbol moves

DarcyHathaway — Fri, 16 Aug 2013 20:57:34 GMT

And yes ArcGIS Engine is what i am using.

Okay please help me figure out if it will work.

Do you have an example?