public void FindDescendentsTest() { var sp = new StackPanel(); var chb = new CheckBox(); var tb = new TextBlock(); const string inputText = "Hello world!"; tb.Text = inputText; chb.Content = tb; sp.Children.Add(chb); var ele = VisualTreeHelpers.FindDescendents <TextBlock>(sp); var tb2 = ele.First(); Assert.AreEqual(inputText, tb2.Text); }