Disable sorting of one row in DataGridView

Question

I'm showing a DataGridView on my VB.NET-GUI. In this table, the last row is a Total-Row which shows an average value. Sorting after columns must actually be possible, but I'd like to fix the Total-Row somehow so it stays the last row. Is this possible or somehow a standard behavior?

Accepted Answer

It seems something like a TotalRow property doesn't exist.

It's possible for sure, by using a custom ordering function.

First, be sure all your columns have `SortMode` set to `Automatic`.

You need somehow to identify your TotalRow, so you can set its `Tag` property to string `"Average"`:

```
row.Tag = "Average"
```

Then add this code:

```
Private Sub DataGridView1_SortCompare(sender As Object,
        e As DataGridViewSortCompareEventArgs) Handles DataGridView1.SortCompare

If (DataGridView1.Rows(e.RowIndex1).Tag = "Average") Then
        e.SortResult = If(DataGridView1.SortOrder = SortOrder.Ascending, 1, -1)
    ElseIf (DataGridView1.Rows(e.RowIndex2).Tag = "Average") Then
        e.SortResult = If(DataGridView1.SortOrder = SortOrder.Ascending, -1, 1)
    Else
        e.SortResult = System.String.Compare(e.CellValue1.ToString(),
                                             e.CellValue2.ToString())
    End If

e.Handled = True

End Sub
```

This will do the trick!

EDIT :

Since you talked about an average value, I assume you want to order elements by their numeric value, instead of ASCII-betically.

If you're sure that your DataGridView will only contain numbers, you can use a greater-than operator instead of the `String.Compare` in the last if branch:

```
e.SortResult = If(e.CellValue1 > e.CellValue2, 1, -1)
```

This way, your numbers will be ordered correctly (10, 20, 100, 200 rather than 10, 100, 20, 200).

If one needs to compare strings and numbers, I'd look for a Natural String Compare algorithm.

Disable sorting of one row in DataGridView

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