PointInShapefile not working anymore in 5.2 and 5.3?

MapWinGIS
1

The PointInShapefile function used to be working on MWG5 but seems to have stopped working in V5.2 and the latest V5.3 (Win 11, VS 2019). I seem to remember there were some problems with it in the past. There is an easy workaround (see vb.net code below), but just for the record for in case I made a mistake…
Cheers,
Francis.

Private Sub _Map_MouseDownEvent(sender As Object, e As _DMapEvents_MouseDownEvent) Handles _Map.MouseDownEvent

Dim ProjX As Double, ProjY As Double
_Map.PixelToProj(e.x, e.y, ProjX, ProjY)
Dim shp As Shapefile = _Map.get_Shapefile(0)
’ Allways returns -1!!
Dim shpindex As Integer = shp.PointInShapefile(ProjX, ProjY)
Dim idx As Integer
’ Works fine
For idx = 0 To shp.NumShapes - 1
If shp.PointInShape(idx, ProjX, ProjY) Then
Exit For
End If
Next
UcMapWinGIS51.tsslMessages.Text = "Idx = " + idx.ToString
End Sub

2

Hello @pan054

I’m sorry I don’t really have time to look further into this, but I do notice that you have not called the BeginPointInShapefile and EndPointInShapefile functions, which build and then tear down a cache. Although I don’t think the calls are necessary, I think that it’s worth trying to see if that makes a difference.

Regards,
Jerry.

3

Hi Jerry,
Thanks for your quick reply, where would we be without you.
It is crazy, but it does indeed work :thinking:! It shouldn’t but it does, so thanks very much for your suggestion!
Cheers
Francis

4

FYI
I compared the ‘do it yourself’ code against the Begin/End code, and found that the Begin/End code is always faster. How much faster depends on the place of the shape in the shapefile table.

5

It’s strange, for some reason BeginPointInShapefile function raises an exception for me. Perhaps something else is needed?