PivotGridControl.CustomFieldSort Event

The event handler receives an argument of type PivotGridCustomFieldSortEventArgs containing data related to this event.

Handle the CustomFieldSort event to provide a custom sorting algorithm for a specific field. Note that the DevExpress.XtraPivotGrid.PivotGridFieldBase.SortMode property of this field should be set to DevExpress.XtraPivotGrid.PivotSortMode.Custom to apply custom sorting. Otherwise, the CustomFieldSort event will not be raised.

The CustomFieldSort event fires for pairs of rows in the underlying data source, before data is grouped according to the layout of column and row fields. The DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.ListSourceRowIndex1 and DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.ListSourceRowIndex2 parameters identify the indexes of the rows. The field being processed is specified by the DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.Field parameter. The field values in these rows are specified by the DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.Value1 and DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.Value2 parameters.

In the event handler, compare these two values and assign the result to the DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.Result property as follows:

• Set the Result to -1 if the first row should be positioned above the second row when data is sorted in ascending order. When data is sorted in descending order, the first row will be positioned below the second row.
• Set the Result to 1 if the first row should be positioned below the second row when data is sorted in ascending order. When data is sorted in descending order, the first row will be positioned above the second row.
• Set the Result to 0 to indicate that the rows are equal. In this case, the compared rows will be grouped into one field value.

If your comparison logic requires additional data from the underlying data source, use the DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.GetListSourceColumnValue method. This method allows you to obtain values from the data source by a column name and row index.

The DevExpress.XtraPivotGrid.PivotGridCustomFieldSortEventArgsBase<T>.Handled parameter should be set to true if the current comparison operation was handled. You can leave this parameter set to false to invoke the default comparison mechanism after your event handler has finished. In the latter instance, the result of the custom comparison operation is ignored.

The CustomFieldSort event also fires to sort unique filter values in the Filter Drop-Down. Each filter value may correspond to multiple rows in the underlying data source. So, the event's ListSourceRowIndex1 and ListSourceRowIndex2 parameters cannot be used to identify underlying rows. They are set to -1 when comparing filter values in the Filter Drop-Down.

This example demonstrates how to implement a custom sorting algorithm by handling the CustomFieldSort event.

The image shows the result:

using DevExpress.XtraPivotGrid;

// fieldResult
this.fieldResult.SortMode = DevExpress.XtraPivotGrid.PivotSortMode.Custom;

private void pivotGridControl1_CustomFieldSort(object sender, 
  PivotGridCustomFieldSortEventArgs e) {
    if (e.Field.FieldName == "Result") {
        if (e.Value1 == null || e.Value2 == null) return;
        e.Handled = true;
        string s1 = e.Value1.ToString().Replace("Result ", String.Empty);
        string s2 = e.Value2.ToString().Replace("Result ", String.Empty);
        if (Convert.ToInt32(s1) > Convert.ToInt32(s2))
            e.Result = 1;
        else
            if (Convert.ToInt32(s1) == Convert.ToInt32(s2))
                e.Result = Comparer<Int32>.Default.Compare(Convert.ToInt32(s1), 
                  Convert.ToInt32(s2));
            else
                e.Result = -1;
    }
}

Imports DevExpress.XtraPivotGrid

' fieldResult
Me.fieldResult.SortMode = DevExpress.XtraPivotGrid.PivotSortMode.Custom

Private Sub pivotGridControl1_CustomFieldSort(ByVal sender As Object, _
  ByVal e As PivotGridCustomFieldSortEventArgs) Handles pivotGridControl1.CustomFieldSort
    If e.Field.FieldName = "Result" Then
        If e.Value1 Is Nothing OrElse e.Value2 Is Nothing Then
            Return
        End If
        e.Handled = True
        Dim s1 As String = e.Value1.ToString().Replace("Result ", String.Empty)
        Dim s2 As String = e.Value2.ToString().Replace("Result ", String.Empty)
        If Convert.ToInt32(s1) > Convert.ToInt32(s2) Then
            e.Result = 1
        Else
            If Convert.ToInt32(s1) = Convert.ToInt32(s2) Then
                e.Result = Comparer(Of Int32).Default.Compare(Convert.ToInt32(s1), _
                  Convert.ToInt32(s2))
            Else
                e.Result = -1
            End If
        End If
    End If
End Sub