public void LimitedWidth() { TabPanel t = new TabPanel(); for (int i = 0; i < 5; i++) { TabItem tab_item = new TabItem(); tab_item.Width = 100; t.Children.Add(tab_item); } t.Measure(new Size(100, double.PositiveInfinity)); Assert.AreEqual(t.DesiredSize.Width, 100, "1"); Assert.AreEqual(t.DesiredSize.Height, 25, "2"); }