Swapping control into a different parent

Colleagues,

What I'm trying to achieve is kind of an undocking behavior, where a control can undock from one form and float in a different form. My code is based on a working reference design. Unfortunately, I ran into a problem. I’m getting an exception when I try to assign a different parent form to the control.

Code:

---

private void FloatPanel()
{
  // this method resides in the new parent form for the control to float in
  // m_ctrlContainer control, which will be swapped into a floating form
  m_ctrlContainer.Parent = this;  // throws exception “Collection is read only.”
}

---

The same exception happens if I call this.Controlls.Add(m_ctrlContainer). It looks like the parent is in a state where controls can’t be added to it. What can I do to add controls to it?

Any suggestion, insight or reference is really appreciated!

- Nick