Hi Sergiy,
The button you marked is actually a scrolling button that allows you to scroll through the tabs of the
RadTabControl. It usually comes up when there are too many tabs in the control and they can't be properly displayed on the screen. If you want to disable this functionality you can set the
ScrollViewer.HorizontalScrollBarVisibility attached property value to
Disabled.
However, please have in mind that when you disable the
ScrollViewer, when there isn't enough space to display all tabs, the control will arrange them in rows. And by default the rows are dynamically reordered to make the row of the currently selected tab first. And you can turn on/of this behavior through the
ReorderTabRows property.
Regards,
Tina Stancheva
the Telerik team