Sub calculate_area(filename As String)
Dim lt, ln As Double
Dim ide As Int
Dim desc As String
Dim bbn As List
Dim polygonoptions1 As PolygonOptions
Dim polygon1 As Polygon
Dim GoogleMapsExtras1 As GoogleMapsExtras
Dim points() As LatLng
bbn.Initialize
sql1.Initialize(filedire,"points.db",True)
Dim cursor1 As Cursor
Dim sqlstring As String= "SELECT * from " & filename
cursor1 =sql1.ExecQuery(sqlstring )
Dim nodata As Int = cursor1.RowCount
Dim points(nodata+1) As LatLng
If cursor1.RowCount > 0 Then
For i = 0 To cursor1.RowCount-1
cursor1.Position=i
ide = cursor1.GetInt("id")
lt=cursor1.GetDouble("lat")
ln=cursor1.GetDouble("lon")
desc=cursor1.GetString("desc")
bbn.Add(lt &","& ln)
points(i).Initialize(lt,ln)
Next
points(nodata).Initialize(points(0).Latitude,points(0).Longitude)
End If
'----------------
Dim puntos As List
puntos.Initialize
For i= 0 To nodata
puntos.Add(points(i))
Next
'---------------------------
polygonoptions1.Initialize
polygonoptions1.FillColor=Colors.ARGB(128, 255, 0, 0)
polygonoptions1.AddPoints(puntos)
polygonoptions1.StrokeColor=Colors.Red
polygonoptions1.StrokeWidth=2
polygon1=GoogleMapsExtras1.AddPolygon(gmap, polygonoptions1)
Dim bb As Navigation
Dim areasqkm,areasqm As Double
areasqkm =bb.SphericalArea(bbn)
areasqm = areasqkm/(1000*1000)
Log(areasqkm & " sqkm")
Log(areasqm & "sqm")
panel_result.Visible=True
label_result.Text= "No of Points" & nodata & CRLF & NumberFormat(areasqkm,1,6) & " sqkm"
cursor1.Close
sql1.Close
End Sub