C# .NET - C# WPF ListView > ItemsSource > SORTING Problem

Hi,

i´d make a descending & ascending Sorting Order for a itemsSource ListView(code below). There is really strange behavior. Sometimes its sorted correct sometimes completly wrong. Sometimes the gridviewcolumnheader reacts by clicking, sometimes not. And if the column contains in one row numbers and in another - words than the sorting is fully shit... How can i offer a certain sorting ?

private void GridViewColumnHeaderClickedHandler(object sender, RoutedEventArgs e) {
            GridViewColumnHeader headerClicked =
                  e.OriginalSource as GridViewColumnHeader;
            ListSortDirection direction;
            if(headerClicked != null) {
                if(headerClicked.Role != GridViewColumnHeaderRole.Padding) {
                    if(headerClicked != _lastHeaderClicked) {
                        direction = ListSortDirection.Ascending;
                    }
                    else {
                        if(_lastDirection == ListSortDirection.Ascending) {
                            direction = ListSortDirection.Descending;
                        }
                        else {
                            direction = ListSortDirection.Ascending;
                        }
                    }
                    string header = headerClicked.Column.Header as string;
                    Sort(header, direction);
                    if(_lastHeaderClicked != null && _lastHeaderClicked != headerClicked) {
                        _lastHeaderClicked.Column.HeaderTemplate = null;
                    }
                    _lastHeaderClicked = headerClicked;
                    _lastDirection = direction;
                }
            }
        }
        private void Sort(string sortBy, ListSortDirection direction) {
            ICollectionView dataView =
              CollectionViewSource.GetDefaultView(listViewRedirectUrl.ItemsSource);
            dataView.SortDescriptions.Clear();
            SortDescription sd = new SortDescription(sortBy, direction);
            dataView.SortDescriptions.Add(sd);
            dataView.Refresh();
        }

Private _CurSortCol As GridViewColumnHeader = Nothing
    Private _CurAdorner As SortAdorner = Nothing


    Private Sub SortClick(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Dim column As GridViewColumnHeader = TryCast(sender, GridViewColumnHeader)
        Dim field As [String] = TryCast(column.Tag, [String])

        If _CurSortCol IsNot Nothing Then
            AdornerLayer.GetAdornerLayer(_CurSortCol).Remove(_CurAdorner)
            lstViewAuditDetails.Items.SortDescriptions.Clear()
        End If

        Dim newDir As ListSortDirection = ListSortDirection.Ascending
        If _CurSortCol.Equals(column) AndAlso _CurAdorner.Direction = newDir Then
            newDir = ListSortDirection.Descending
        End If

        _CurSortCol = column
        _CurAdorner = New SortAdorner(_CurSortCol, newDir)
        AdornerLayer.GetAdornerLayer(_CurSortCol).Add(_CurAdorner)
        lstViewAuditDetails.Items.SortDescriptions.Add(New SortDescription(field, newDir))
    End Sub

Here full code
http://weblogs.asp.net/marianor/archive/2007/12/14/sorting-a-listview-data-source-in-wpf.aspx

Thank you
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