LISTBOX - is it possible to sort by number instead of string

Richard_And_Trisha

column header sort by number instead of string. eg price or amount column or just a number column?

rgb

Richard_And_Trisha

Hi @Richard_And_Trisha,

Add Handler event "HeaderPressed"

Remove All Rows
Sort your array with your parameters
Set all rows

Richard_And_Trisha

so refresh the query attach to the listbox according the column click on in header pressed and reload the data again??

Garry

Yes. ListBox has built-in type-aware sorting.

Set:

lb.ColumnSortable = True

Then clicking a column header sorts that column. The built-in sort tries numbers first, then dates, then text, so plain values like 2, 10, 12.5 should sort numerically rather than alphabetically.

You can also do it manually:

    lb.Sort(column, True)

One caveat: ListBox cells store displayed text. So plain numeric text should work, but formatted currency like £12.50, $1,234.00, or locale-specific formats may not currently sort as numbers. In that case, sort your backing data/query yourself and reload the ListBox.

If plain numbers are sorting as strings, please post a small example and the Studio version, because that would be a bug.

bgrommes

Garry Re trying to sort numerically, etc. You are faced with scanning potentially thousands of rows to confirm there aren't scattered alphanumerics in there. (For example you could have an account # field, which is mostly all digits but a few legacy accounts or accounts imported from another company via a merger had alphanumerics). The OleDb text drivers (importing CSVs) used to get around this by searching some # of rows and then assuming that was fully representative, sometimes with bad results. Toward the end I think you could set the # of scanned rows or request that they all be scanned.

All in all I didn't love this quirk and would prefer that at some point we are just dealing with typed columns to begin with (or at least the control knows the backing type and goes by that).

That said, the fact you can explicitly request numeric sorting helps a great deal here.

Richard_And_Trisha

I have a listbox In xojo that can click on the column header and sort by date yyyy-mm-dd internally but shown as dd/mm/yyyy. also I have another that sort by number padded with 0 but show as integer or double.. so my listbox has a cell tag with value for sorting.

also when come to showing numbers or amount column, it need be able to show aligned right, and other string is aligned left. don't know if I require center alignment

Garry

Yes, that makes sense. What you are describing is slightly different from plain numeric sorting: you want the ListBox to display one value but sort by another hidden/typed value.

At the moment, Objo’s built-in ListBox sort works from the displayed cell text. That handles simple values like 2, 10, and 12.5, and simple sortable dates, but it does not currently use CellTag as a hidden sort key.

For now, the reliable approach is to leave ColumnSortable as False, handle HeaderPressed(), sort your backing array/query using the real typed value, and reload the ListBox.

I think the right longer-term addition might be explicit ListBox support for this, probably something like a per-cell sort value/sort key, plus per-column text alignment using the existing TextAlignment values. I’d rather not silently make CellTag drive sorting because tags are also useful for record IDs or arbitrary app metadata, and that could surprise people.

Right-aligning number/currency columns is also a reasonable ListBox feature request. You can do it today with custom drawing, but it should probably be a simple column setting: https://feedback.objo.dev/feature/444

Richard_And_Trisha

I mean that is currently what I do in Xojo to get them to sorted properly.

if you can provide something better, I will be so grateful and delighted

how to I perform the right alignment sorting using custom drawing??

it will be wonderful to have the right alignment setting in code.

Garry

In the current build, sorting and right alignment are separate.

ListBox.Sort() still sorts from the cell text, so for formatted values use the cell text as the sortable key and use CellTag for the displayed value. Then custom draw the formatted value right-aligned.

# Example row setup:
Var amount As New Currency(100)
Var row As Integer = lb.AddRow(["2026-06-15", amount.ToString("0.00", Locale.Invariant)])

lb.SetCellTag(row, 0, "15/06/2026")
lb.SetCellTag(row, 1, "£" + amount.ToString("N2"))
lb.ColumnSortable = True

In the ListBox lb's PaintCellText() event handler:

If column <> 0 And column <> 1 Then Return False

Var text As String

If lb.CellTagAt(row, column) = Nothing Then
    text = lb.CellTextAt(row, column)
Else
    text = lb.CellTagAt(row, column).ToString()
End If

If selected Then
    g.DrawingColour = ThemeColours.SelectionText
Else
    g.DrawingColour = Colour.Black
End If

If column = 1 Then
    g.TextAlignment = TextAlignment.Right
    g.DrawText(text, g.Width - x, y)
Else
    g.DrawText(text, x, y)
End If

Return True