Imports Infragistics.Win
Imports Infragistics.Win.UltraWinTabs
' Close the first tab in the tab control. This will set the tab's Visible property to False.
Me.UltraTabbedMdiManager1.TabGroups(0).Tabs(0).Close()
using System.Windows.Forms;
using Infragistics.Win;
using Infragistics.Win.UltraWinTabs;
// Close the first tab in the tab control. This will set the tab's Visible property to False.
this.ultraTabbedMdiManager1.TabGroups[ 0 ].Tabs[ 0 ].Close();