RowIsExpandedChanged and CollapseHierarchyItem

[imad]

Hi,

I am trying to have a single expand Hierarchy in my GridView, in the RowIsExpandedChanged events i am checking if the row is expanded and i am collapsing the other rows with the CollapseHierarchyItem.

What is happening is that the RowIsExpandedChanged event is raised again when calling CollapseHierarchyItem, how to collapse rows without firing the RowIsExpandedChanged events.

Thanks.

[Maya]

Hi imad,

You may handle the RowIsExpandedChanged as follows:

GridViewRow lastExpandedRow;

private void clubsGrid_RowIsExpandedChanged(object sender, Telerik.Windows.Controls.GridView.RowEventArgs e)

        {

            if((e.Row as GridViewRow).IsExpanded)

            {

                if(lastExpandedRow != null)

                {

                    lastExpandedRow.IsExpanded = false;

                }

                lastExpandedRow = e.Row as GridViewRow;

            }

        }

This approach is similar to the one described in this blog post referring an equal scenario but with RowDetails.
 

Greetings,
Maya
the Telerik team

[imad]

Thanks Maya for the answer,

But I Have 2 issues, First the lastExpandedRow.IsExpanded = false will refire the Event, this works fine in the example you gave but In my case i have

private void clubsGrid_RowIsExpandedChanged(object sender, Telerik.Windows.Controls.GridView.RowEventArgs e)
        {
            if((e.Row as GridViewRow).IsExpanded)
            {
                if(lastExpandedRow != null)
                {
                    lastExpandedRow.IsExpanded = false;
                }
                lastExpandedRow = e.Row as GridViewRow;
            }
            else{ // do some action}
        }

so the else action will be fired for the previously expanded row.

Second I dynamically instantiate grids from database (depending on some categories defined),
and i am attaching these instances events, so i need to keep a collection of lastRow per grid. 

Any solution for my case?

Thanks

[Milan]

Hi imad,

You could try this modified version of the code:

private bool changing = false;

void clubsGrid_RowIsExpandedChanged(object sender, RowEventArgs e)
{
    if(changing)
        return;

    this.changing = true;

    if ((e.Row as GridViewRow).IsExpanded)
    {
        this.clubsGrid.CollapseAllHierarchyItems();
        this.clubsGrid.ExpandHierarchyItem(e.Row.DataContext);

        //lastExpandedRow = e.Row as GridViewRow;
    }

    this.changing = false;
}

Notice the introduction of a special flag variable that guards the expand/collpase code of being executed multiple times.

All the best,
Milan
the Telerik team