Dataview confusion

[adam.syd]

Hi All,

I am new to VB.Net and I have noticed somthing strange with dataviews.
The code below does not move through the dataview but displays only the results for the first record.

For i = 0 To dv.Count - 1
            'dv(i).BeginEdit()
            Console.WriteLine(dv(i)("Machine") & ": " & dv(i)("Display"))
            'dv(i).EndEdit()
        Next

The code below shows all the details correctly.

Dim myDRV As DataRowView
        For Each myDRV In dv
            Console.WriteLine(myDRV("Machine") & ": " & myDRV("Display"))
        Next

As I said I am new to VB.Net so if someone could point out my mistake it would be appreciated.

Regards,
Adam.

[jmcilhinney]

You must be doing something else wrong because they both work for me.

[adam.syd]

Thanks for replying, I am updating the rows on the first pass. When I move through the rows a second time it appears to get stuck on the first row.
I have tried using the 'BeginEdit' & 'EndEdit' during the update but they do not appear to fix the problem.

dv(i)("ActualDisplayOrder") = i + 1
etc....

Sorry I did not mention this, I thought I might have had the basic code incorrect.

Cheers,
Adam.

[jmcilhinney]

I think you need to show the full code.

[adam.syd]

Hi jmcilhinney,

The code I have inherited is shown below. The issue is when the aShow(i) is being loaded. 'dv(i)("Display")' gives the array the correct value the first time the procedure is run but after that the loop appears to get stuck on the first record. It is quite interesting as when I use a 'dataRow' to enumerate through the dataview it gives the correct values. I have tried using 'BeginEdit' & 'EndEdit' but it does not correct it. Maybe it is because I am using a filter & sorting. The dataview is getting updated but it gets stuck on the first records as noted above.

Any ideas would be appreciated ?

' Class variable
    Public dsMch As New DataSet
Private Sub ChangeValue(ByVal blnUp As Boolean)
 
        Dim aRow As DataRow
        Dim dv As DataView
        Dim iMax As Integer
        Dim i As Integer
        Dim aShow() As Boolean
        Dim blnCurrentDisplay As Boolean
 
        dv = New DataView(Me.dsMch.Tables(0))
        dv.AllowEdit = True
        dv.AllowDelete = False
        dv.AllowNew = False
 
        dv.RowFilter = "Display = True OR Source = 'Schedule'"
        dv.Sort = "ActualDisplayOrder ASC"
 
        ReDim aShow(dv.Count - 1)
 
        If blnUp Then
            ' Increment ActualDispalyOrder
            ' Set all DisplayOrders to 999
            For i = 0 To dv.Count - 1
                'dv(i).BeginEdit()
                dv(i)("DisplayOrder") = 999
                Console.WriteLine(dv(i)("Machine") & ": " & dv(i)("Display"))
               '**** Incorrect values when called more than once *****
                aShow(i) = dv(i)("Display")
                If i = dv.Count - 1 Then
                    ' Set last value to zero
                    dv(i)("ActualDisplayOrder") = 0
                Else
                    ' Increment Actual display
                    dv(i)("ActualDisplayOrder") = i + 1
                End If
                'dv(i).EndEdit()
            Next
        Else
 
        End If
 
        ' Sort by ActualDisplayOrder & set flag to show as 
        ' per array
        'dv.Sort = vbNullString
        dv.Sort = "ActualDisplayOrder ASC"
        For i = 0 To dv.Count - 1
            dv(i).BeginEdit()
            dv(i)("Display") = aShow(i)
            dv(i).EndEdit()
        Next
 
        ' Update display order used to show machines
        dv.RowFilter = vbNullString
        dv.RowFilter = "Display = True AND Source = 'Schedule'"
        dv.Sort = "ActualDisplayOrder ASC"
        For i = 0 To dv.Count - 1
            dv(i).BeginEdit()
            dv(i)("DisplayOrder") = i
            dv(i).EndEdit()
        Next
End Sub