I'm developing an application in MS Access 2016 using the MapWinGIS.ocx. My code is working reasonably well but I need to add some simple functionality (like adding labels to markers on the map).
My markers are created manually using the DrawWideCircleEx function inside a loop based on an Access recordset. The markers are drawn correctly on a layer added to the map. Immediately after drawing the marker I try to apply a label to it using the DrawLabel function. I've debugged the code and find that the DrawLabel function seems to crash Access - immediately.
I'm not absolutely sure this is the appropriate forum for asking for help or if anyone has encountered this problem, but any suggestion / help is greatly appreciated - and thanks in advance.
Here's a snippet of the code that's causing the crash.
The offending statement labelReturn = CountyMap.DrawLabel("Text", pX, pY, 0) is commented out for now.
Do While Not rst3.EOF
mapLat = rst3!D_LATITUDE
mapLon = rst3!D_LONGITUDE
markerSize = rst3!D_GTOTAL / 1000
xlate = CountyMap.DegreesToPixel(mapLon, mapLat, pX, pY)
If (xlate) Then
Select Case markerSize
Case Is >= 20
markerSize = CountyMap.DrawWideCircleEx(hndDrawLayer, pX, pY, 16, RGB(255, 0, 0), False, 2)
'labelReturn = CountyMap.DrawLabel("Text", pX, pY, 0)
Case Is >= 10
markerSize = CountyMap.DrawWideCircleEx(hndDrawLayer, pX, pY, 8, RGB(255, 0, 0), False, 2)
Case Else
markerSize = CountyMap.DrawWideCircleEx(hndDrawLayer, pX, pY, 4, RGB(255, 0, 0), False, 2)
End Select
Else
End If
rst3.MoveNext
Loop
Comments: Hi Rick - I'm building an access application as well. I wound up using a separate call to convert basic lat/lon coordinates to project coordinates on a map, but I'm using a shapefile method. First, here are the two converters: Function projectlat(latitude) Dim pi As Double pi = 3.141592654 projectlat = Log(Tan(latitude * (pi / 180) / 2 + pi / 4)) * 6378137 End Function Function projectlon(longitude) Dim pi As Double pi = 3.141592654 projectlon = longitude * (pi / 180) * 6378137 End Function Then, here's the routine I use to store and display the labels. Sub addpeopleLabels(map As Form) Dim label As String Dim x As Double Dim y As Double Dim i As Integer Dim putils As MapWinGIS.Utils Dim rs As Recordset Dim db As Database Set putils = New Utils Set db = CurrentDb Set rs = db.OpenRecordset("select * from clients where not (latitude)is null and not (longitude) is null") Do While Not rs.EOF label = rs!FirstName & " " & rs!LastName & Chr(10) & Chr(13) & Format(rs!Phone, "(###) ###-####") x = projectlon(rs!longitude) y = projectlat(rs!latitude) sfpeople.labels.AddLabel label, x, y, 0, 0 rs.MoveNext Loop sfpeople.labels.FrameVisible = True sfpeople.labels.options.ShadowVisible = True End Sub I declare the shapefile (in this case, sfpeople) as global variables. Once I have the shapefile built, I can turn the labels on with a simple command: sfpeople.labels.Visible = True I hope this helps - good luck on your project - Ray
My markers are created manually using the DrawWideCircleEx function inside a loop based on an Access recordset. The markers are drawn correctly on a layer added to the map. Immediately after drawing the marker I try to apply a label to it using the DrawLabel function. I've debugged the code and find that the DrawLabel function seems to crash Access - immediately.
I'm not absolutely sure this is the appropriate forum for asking for help or if anyone has encountered this problem, but any suggestion / help is greatly appreciated - and thanks in advance.
Here's a snippet of the code that's causing the crash.
The offending statement labelReturn = CountyMap.DrawLabel("Text", pX, pY, 0) is commented out for now.
Do While Not rst3.EOF
mapLat = rst3!D_LATITUDE
mapLon = rst3!D_LONGITUDE
markerSize = rst3!D_GTOTAL / 1000
xlate = CountyMap.DegreesToPixel(mapLon, mapLat, pX, pY)
If (xlate) Then
Select Case markerSize
Case Is >= 20
markerSize = CountyMap.DrawWideCircleEx(hndDrawLayer, pX, pY, 16, RGB(255, 0, 0), False, 2)
'labelReturn = CountyMap.DrawLabel("Text", pX, pY, 0)
Case Is >= 10
markerSize = CountyMap.DrawWideCircleEx(hndDrawLayer, pX, pY, 8, RGB(255, 0, 0), False, 2)
Case Else
markerSize = CountyMap.DrawWideCircleEx(hndDrawLayer, pX, pY, 4, RGB(255, 0, 0), False, 2)
End Select
Else
End If
rst3.MoveNext
Loop
Comments: Hi Rick - I'm building an access application as well. I wound up using a separate call to convert basic lat/lon coordinates to project coordinates on a map, but I'm using a shapefile method. First, here are the two converters: Function projectlat(latitude) Dim pi As Double pi = 3.141592654 projectlat = Log(Tan(latitude * (pi / 180) / 2 + pi / 4)) * 6378137 End Function Function projectlon(longitude) Dim pi As Double pi = 3.141592654 projectlon = longitude * (pi / 180) * 6378137 End Function Then, here's the routine I use to store and display the labels. Sub addpeopleLabels(map As Form) Dim label As String Dim x As Double Dim y As Double Dim i As Integer Dim putils As MapWinGIS.Utils Dim rs As Recordset Dim db As Database Set putils = New Utils Set db = CurrentDb Set rs = db.OpenRecordset("select * from clients where not (latitude)is null and not (longitude) is null") Do While Not rs.EOF label = rs!FirstName & " " & rs!LastName & Chr(10) & Chr(13) & Format(rs!Phone, "(###) ###-####") x = projectlon(rs!longitude) y = projectlat(rs!latitude) sfpeople.labels.AddLabel label, x, y, 0, 0 rs.MoveNext Loop sfpeople.labels.FrameVisible = True sfpeople.labels.options.ShadowVisible = True End Sub I declare the shapefile (in this case, sfpeople) as global variables. Once I have the shapefile built, I can turn the labels on with a simple command: sfpeople.labels.Visible = True I hope this helps - good luck on your project - Ray