Custom Sorting Not Updating Order

[Andrew]

I'm using the custom Telerik.Data.DataTable to bind my grid. I have implemented a custom DateTime sort as follows:

protected void CISGrid_Sorting(object sender, GridViewSortingEventArgs e)
{
    Telerik.Data.DataTable table;

    this.sortingHeaderField = CollectionUtil.GetItemFromCollectionByProperty(this.Layout.HeaderFields, "Description", e.Column.UniqueName) as HeaderField;

    if (this.sortingHeaderField.Control == HeaderField.ControlType.Date)
    {
        table = e.DataControl.ItemsSource as DataTable;

        if (e.NewSortingState == SortingState.Ascending)
        {
            table.Rows.Sort(CompareDatesAscending);

            e.DataControl.ItemsSource = table;
            e.Cancel = true;
        }
        else if (e.NewSortingState == SortingState.Descending)
        {
            table.Rows.Sort(CompareDatesDescending);

            e.DataControl.ItemsSource = table;
            e.Cancel = true;
        }
    }
}
private int CompareDatesDescending(DataRow r1, DataRow r2)
{
    return CompareDates(r1, r2, true);
}

private int CompareDatesAscending(DataRow r1, DataRow r2)
{
    return CompareDates(r1, r2, false);
}

private int CompareDates(DataRow r1, DataRow r2, bool descending)
{
    DateTime dateTime1;
    DateTime dateTime2;

    DateTime.TryParseExact(r1[this.sortingHeaderField.Description].ToString(), this.sortingHeaderField.InputFormat, System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out dateTime1);

    DateTime.TryParseExact(r2[this.sortingHeaderField.Description].ToString(), this.sortingHeaderField.InputFormat, System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out dateTime2);

    if (descending)
    {
        return DateTime.Compare(dateTime1, dateTime2);
    }
    else
    {
        return DateTime.Compare(dateTime2, dateTime1);
    }
}

Everything sorts as exepected in the DataTable but the RadGridView never updates to show the new sorting order.

Am I doing something wrong?

[Milan]

Hello Andrew,

I believe this is not working because the same DataTable instance is set as ItemsSource which - the ItemsSource property does not actually change. You could try setting ItemsSource to null or simply calling Rebind.

if (this.sortingHeaderField.Control == HeaderField.ControlType.Date)
    {
        table = e.DataControl.ItemsSource as DataTable;
        // clear item source
        e.DataControl.ItemsSource = null;

        if (e.NewSortingState == SortingState.Ascending)
        {
            table.Rows.Sort(CompareDatesAscending);

            e.DataControl.ItemsSource = table;
            e.Cancel = true;
        }
        else if (e.NewSortingState == SortingState.Descending)
        {
            table.Rows.Sort(CompareDatesDescending);

            e.DataControl.ItemsSource = table;
            e.Cancel = true;
        }
    }

// or ...

if (this.sortingHeaderField.Control == HeaderField.ControlType.Date)
    {
        table = e.DataControl.ItemsSource as DataTable;

        if (e.NewSortingState == SortingState.Ascending)
        {
            table.Rows.Sort(CompareDatesAscending);

            e.Cancel = true;
        }
        else if (e.NewSortingState == SortingState.Descending)
        {
            table.Rows.Sort(CompareDatesDescending);

            e.Cancel = true;
        }

        e.DataControl.Rebind();
    }

I hope this makes sense.

Regards,
Milan
the Telerik team

[Andrew]

Neither method works, my grid still doesn't update with the new sort order and I have no idea why not.

[Milan]

Hello Andrew,

I believe that you are using our DataTable implementation. May I ask you if that is correct? I would also appreciate it if you can share the implementation of the Sort method that you are using.

Greetings,
Milan
the Telerik team

[Raj]

Hi Telerik Team,
I have one issue after Telerik Grid sort,sorting order changing in the Grid, but not updating the underlying dataset,with this i am unable to delete/update the right record from dataset.For deleting/updating iam using the e.Item.DatasetIndex.
with out using any DataKeyName for delete/update,i need the solution.

Thanks,
Raj