topic Using a nested loop in ArcObjects SDK Questions

Using a nested loop

DemetrisDemetriou — Tue, 18 Oct 2011 05:45:53 GMT

I use the following nested loops to read the first point feature of a dataset and the rest points in that dataset. Then read the second point feature of a dataset and the rest points in that dataset and so on. The problem with these nested loops is that it reads the first point and the rest points only once. Why this happens?

    Dim pFCursor As IFeatureCursor
    Set pFCursor = pFeatureClass.Search(Nothing, True)

    Dim pFCursor2 As IFeatureCursor
    Set pFCursor2 = pFeatureClass.Search(Nothing, True)

    Dim pFeature As IFeature
    Dim pFeature2 As IFeature

    Dim pPointA As IPoint
    Dim pPointB As IPoint

    Set pFeature = pFCursor.NextFeature
    Do Until pFeature Is Nothing

    Set pPointA = pFeature.Shape

    MsgBox pFeature.Value(intPosFID) & "F1"

       Set pFeature2 = pFCursor2.NextFeature
       Do Until pFeature2 Is Nothing

             Set pPointB = pFeature2.Shape

             MsgBox pFeature2.Value(intPosFID) & "F2"

       Set pFeature2 = pFCursor2.NextFeature
       Loop

      Set pFeature = pFCursor.NextFeature
       Loop

Re: Using a nested loop

DuncanHornby — Sat, 11 Dec 2021 19:47:41 GMT

I think you need to reset the second feature cursor with each loop of your first feature cursor. You code should look like:

Dim pFCursor As IFeatureCursor
Set pFCursor = pFeatureClass.Search(Nothing, True)
Dim pFCursor2 As IFeatureCursor
Dim pFeature As IFeature
Dim pFeature2 As IFeature
Dim pPointA As IPoint
Dim pPointB As IPoint

Set pFeature = pFCursor.NextFeature
Do Until pFeature Is Nothing

    Set pPointA = pFeature.Shape
    MsgBox pFeature.Value(intPosFID) & "F1"
    Set pFCursor2 = pFeatureClass.Search(Nothing, True)
    Set pFeature2 = pFCursor2.NextFeature
    Do Until pFeature2 Is Nothing
        Set pPointB = pFeature2.Shape
        MsgBox pFeature2.Value(intPosFID) & "F2"
        Set pFeature2 = pFCursor2.NextFeature
    Loop
    Set pFeature = pFCursor.NextFeature
Loop

Duncan

p.s. Please place your code samples inside the code tags (the # symbol on the toolbar)

Re: Using a nested loop

DemetrisDemetriou — Tue, 18 Oct 2011 09:08:31 GMT

Yes, Duncan. You are right! That was the mistake. Thank you very much.
Demetris