Question

Does the number of controls on a form affect its performance? What if the controls are marked invisible? What if the several controls are visible, but entirely covered by only a few controls (like a panel containing a couple of controls)?

I’m asking this from a perspective of applications like 3d modeling packages, video editing software, etc. They’ve got hidden panels, tabs, rollouts, animated drawers and what not.

Has anyone done any such performance tests? Is considering this worthwhile?

Answer 1

Without doing any performance test it’s easy to say that too many controls has performance issue,

• The memory usage increased (UI objects are very huge).
• OnPaint and other message base
  methods will be called (for control
  or for parent in inheritance
  hierarchy)