Retain the user defined sort order in WPF DataGrid

Question

I have a WPF DataGrid that is populated with data from DataSet. I have CanUserSortColumns set to true.

Is it possible to retain the sorting that the user specified when the grid is refreshed? I have it retaining the item that was selected using

  object selectedItem = dgInvoiceHeads.SelectedItem;

before the refresh takes place and then placing

 dgInvoiceHeads.SelectedItem = selectedItem;

after the refresh takes place.

But I can't seem to get it to retain the specified sort.

Answer 1

The following code was pulled from this forum post and it shows how to obtain the sort descriptions and column information and restore it.

List<DataGridColumn> GetColumnInfo(DataGrid dg) {
    List<DataGridColumn> columnInfos = new List<DataGridColumn>();
    foreach (var column in dg.Columns) {
        columnInfos.Add(column);
    }
    return columnInfos;
}

List<SortDescription> GetSortInfo(DataGrid dg) {
    List<SortDescription> sortInfos = new List<SortDescription>();
    foreach (var sortDescription in dg.Items.SortDescriptions) {
        sortInfos.Add(sortDescription);
    }
    return sortInfos;
}

void SetColumnInfo(DataGrid dg, List<DataGridColumn> columnInfos) {
    columnInfos.Sort((c1, c2) => { return c1.DisplayIndex - c2.DisplayIndex; });
    foreach (var columnInfo in columnInfos) {
        var column = dg.Columns.FirstOrDefault(col => col.Header == columnInfo.Header);
        if (column != null) {
            column.SortDirection = columnInfo.SortDirection;
            column.DisplayIndex = columnInfo.DisplayIndex;
            column.Visibility = columnInfo.Visibility;
        }
    }
}

void SetSortInfo(DataGrid dg, List<SortDescription> sortInfos) {
    dg.Items.SortDescriptions.Clear();
    foreach (var sortInfo in sortInfos) {
        dg.Items.SortDescriptions.Add(sortInfo);
    }
}

Answer 2

Have you tried getting the collectionview for the dataset?

CollectionViewSource.GetDefaultView(yourDataSet).SortDescriptions

This will give you an array of the current sortdescriptions. You can then persist these, and the next time round apply them as follows

CollectionViewSource.GetDefaultView(yourDataSet).SortDescriptions.Add(...)

Hope it helps.