
Using the Collection Editor
You can also add tab items to a TabControl by using the collection editor. When you use the collection editor to configure tab items, Design view and XAML view are updated automatically.
To add tab items to a TabControl by using the collection editor
In the WPF Designer, select a TabControl.
In the Properties window, locate the Items property, and click the ellipsis button in the property value column.
The Collection Editor dialog box appears.
Click Add to add a new tab item.
(Optional) Set the properties of the tab item.
(Optional) Repeat steps 3 and 4 to add more tab items.
Click OK to close the Collection Editor and return to the WPF Designer.