Question

How do I show a MDIChild Form always on top of other MDIChild Forms ?

I have set TopMost property of the ChildForm to True, But the form still behaves the same way…

I have tried to set TopLevel property of ChildForm to True and got the error message… “Top-level Style of a Parented control cannot be changed.”

How do I achieve this.

Thanks

Answer 1

The framework apparently does not support MDI child windows owning each other so you have to simulate that behavior yourself:

  static Form f1 = new Form();
  static Form f2 = new Form();
  static Form f3 = new Form();

  [STAThread]
  static void Main()
  {
     f1.IsMdiContainer = true;
     f2.MdiParent = f1;
     f3.MdiParent = f1;
     f1.Show();
     f2.Show();
     f3.Show();
     f2.Activated += new EventHandler(f2_Activated);
     Application.Run(f1);
  }

  static void f2_Activated(object sender, EventArgs e)
  {
     f3.Activate();
  }

I generally just make owned forms not be MDI child forms. They don’t stay in the MDI container, but at least they stay in front.

Perhaps the reason this limitation exists is because of the strange or ambiguous desired behavior when the MDI child that is the owner is maximized within the container. the above code will allow the owned form to go behind the maximized parent if you click on it in this case. If you have it outside the container, though, then it will remain visible.