Create a user control from existing objects
In Microsoft Expression Blend, you can select a container of objects and make them into a user control, which you can then reuse in your project, or in other projects.
In the Objects and Timeline panel, hold down the CTRL key when you select all the objects that you want to become the new user control. Alternatively, you can use the Selection tool when you hold down the CTRL key to select the objects on the artboard.
Only objects that are contained in the same parent object can be grouped into a new user control.
Do one of the following:
Right-click the selection and then click Make Into UserControl.
On the Tools menu, click Make Into UserControl (F8).
The Make Into UserControl dialog box appears.
In the Name field, enter a name for your new user control.
If you want to create the new user control without replacing the original elements in your document, select the Leave original content as is and create duplicates as necessary box.
Expression Blend creates a new user control document and opens it for additional editing.
Switch back to your original document. If you allowed Expression Blend to replace the selected controls with the new user control, you will have to build your project to see the new control. On the Project menu, click Build Project (CTRL+SHIFT+B).
When you use the Make Into UserControl command, the selected objects, their referenced resources, and referenced animations are refactored into the new user control. However, if the objects include event handler methods in the code-behind file of the original document, you will have to copy the event handler code to the code-behind file of the new user control document.