> How can I query a Windows.Form control if it is hidden or not.
The Visible property of the control.
Two places to look for this information in the future:
1) MSDN:
http://msdn.microsoft.com/en-us/libr...trol.hide.aspx
"Hiding the control is equivalent to setting the Visible property to
false. After the Hide method is called, the Visible property returns a
value of false until the Show method is called."
2) If MSDN doesn't have the information you need, try Reflector:
http://www.aisto.com/roeder/dotnet/
....which will give you this as the reflected method body of Hide()
public void Hide()
{
this.Visible = false;
}