If you open that TabControl.xaml in our XamlPlayer, does it look fine? What theme are you using in your application? How is POCtwo.xaml including the TabControl xaml? Is it possible that its contained in a panel with not enough space for rendering the whole tab control? i just created the Tabcontro...

just created a tabControl which which contains of two tabitems and the tabcontrol is created in the file TabControl.xaml and i registered it in the Main.Cpp and it's header also. When we view the design in the visualstudio the design looks good and i call the TabControl.xaml inside another file POCt...