DatagridView loses seems to lose columns

Question

I have an application in which a datagrid is filled with data

I create all the columns at runtime and then fill the rows

Works fine

But in the same form are several other datagridviews
When the user rightclicks on the other datagrid i perform some actions and then want to modify the content of one cell in the first datagrid

But when he tries i get a index out of bound.
In the debugger i see that row and columncount are 0

While i have several rows and 35 columns

Answer 1

Hi @Frank Kosterman ,
The part of the code where the rows/columns are added looks fine.
It is recommended that you do step-by-step debugging and use Watch to monitor RowCount and ColumnCount to see at which step the value goes wrong.

Best Regards.
Jiachen Li

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Answer 2

Hello

I already did that

I created 35 columns at runtime with the command

nColCount = rs.Fields.Count
Me.dgView.ColumnCount = nColCount

on the breakpoint nRow = 3 and nCell =33

So they are all in range

But when i inspect me.dgview.rowcount, it gives me zero

Answer 3

 Dim rs As ADODB.Recordset
        Dim strSql As String

        Dim nColCount As Integer
        Dim nCol As Integer
        Dim strColName As String
        Dim strColType As String
        Dim strColTemp As Object
        Dim nColWidth As Integer
        Dim nDgRow As Integer
        Dim strRegKey As String
        Dim strEnableColumn As String
        Dim nColorRow As Long


        Me.dgView.EnableHeadersVisualStyles = False

        Me.dgView.Rows.Clear()

        oColType = New Collection

        strSql = "Select * from " + SetTable + "_" + strCurrentModality

        rs = New ADODB.Recordset
        rs.CursorType() = ADODB.CursorTypeEnum.adOpenDynamic

        rs.Open(strSql, cn,, ADODB.LockTypeEnum.adLockOptimistic)

        nColCount = rs.Fields.Count

        Me.dgView.ColumnCount = nColCount
        'Initialise columns

        For nCol = 0 To nColCount - 1

            strColName = rs.Fields(nCol).Name
            strColType = rs.Fields(nCol).Type
            strColTemp = rs.Fields(nCol).Properties
            nColWidth = rs.Fields(nCol).ActualSize


            Me.dgView.Columns(nCol).HeaderText = strColName
            Me.dgView.Columns(nCol).Name = strColName
            Me.dgView.Columns(nCol).SortMode = False
            Select Case strColType
                Case cTypeString

                Case cTypeDate
                    Me.dgView.Columns(nCol).DefaultCellStyle.Format = cDateFormat
                    Me.dgView.Columns(nCol).Width = 80

            End Select

            Me.dgView.Columns(nCol).Tag = strColType

        Next
        'Column headers done, now retrieve data
        rs.MoveFirst()
        Do While Not rs.EOF
            nDgRow = Me.dgView.Rows.Add()
            For nCol = 0 To nColCount - 1
                dgView.Rows(nDgRow).Cells(nCol).Value = rs.Fields(nCol).Value

            Next
            nColorRow = FindColorRow(dgView.Rows(nDgRow).Cells(nColPoNumber).Value)
            If nColorRow > -1 Then
                'Er is een kleur definitie gevonden nu verwerken
                ProcessColors(nColorRow, nDgRow)
            End If
            rs.MoveNext()
        Loop

        rs.Close()

    End Sub

Answer 4

I went trough the code in debug mode and noticed the exact moment when the col and rowcount became zero

It was in a function that was called from the class that i created
that function is placed in the form

I have 5 instances of that class in my form, btw these are also datagridviews

Then i added some code in a combobox to call this function

Now the col and rowcount stayed good

So i took out the class code and placed it on the 5 instances and now it worked

   Private Sub DgInschrijvingen_MouseDown(sender As Object, e As MouseEventArgs) Handles Me.MouseDown
    Dim nKleur As Color
    Dim oKleur As Kleur
    If e.Button = MouseButtons.Right Then
            oKleur = frmVerzamelstaat.KiesKleur(nPos)     ' ' this will call the colordialog box
            If oKleur.IsKleurGekozen Then
               nKleur = oKleur.GekozenKleur
               MyBase.BackgroundColor = nKleur
               MyBase.Columns(0).DefaultCellStyle.BackColor = nKleur
            End If
    End If
    End Sub