How to: Set Up Automatic Menu Merging for MDI Applications
.NET Framework 4.6 and 4.5
The following procedure gives the basic steps for setting up automatic merging in a multiple-document interface (MDI) application with MenuStrip.
To set up automatic menu merging
Create the MDI parent form by setting its IsMdiContainer property to true.
Create an MDI child form, and set its MdiParent property to the name of the parent form.
Add menu items to the child form's MenuStrip that you want to merge into the parent form's MenuStrip when the child form is activated.
Use the MergeAction property on the menu items in the child form's MenuStrip to control how they merge into the parent form.