IsMdiContainer

[MarwaAlSagheer]

Why when I set IsMdiContainer property to true for MdiParent form some controls of this form will be in gray color and all controls will change their position , and how to show Mdichild form on the top of MdiParent ?

How can I open more than one child form and present them like MdiLayout.TileH orizontal without using Mdi method ??

[Plater]

Making a form a mdiparent changes its layout, it no longer expects controls to exist directly on it.
On all child forms you have to remember to explicitly set the TopMost property to false.