DataGridView sorting with nulls in DateTime column

Question

I\'ve got a DataGridView control in a Windows forms application. There are four columns with string data and three with DateTime data. I\'m adding the rows programmatically

Answer 1

An easy solution is to add a "tonull" function, which you run the e.cellvalue1 and 2 through each time a comparison is made. If the value is "" then the value of the cell will be changed to 01/01/1001 if you want null values to appear first on the sort or 01/01/3001 or something ridiculously high if you want them to appear last on the sort.

Private Sub dgvTable_SortCompare(ByVal sender As Object, ByVal e As DataGridViewSortCompareEventArgs) Handles dgvTable.SortCompare

    If e.Column.Index = 4 Then

        e.SortResult = System.DateTime.Compare(todatenull(e.CellValue1), todatenull(e.CellValue2))

    End If

    e.Handled = True
End Sub


Function todatenull(ByVal cellvalue)
    If cellvalue = "" Then
        Return "01/01/1001"
    Else
        Return cellvalue
    End If
End Function