Control.SetTopLevel Method (Boolean)
Sets the control as the top-level control.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
If you call the Form and pass in a value of false, the form will not be visible until you call again, passing in a value of true.method of a
to set the control as a top-level control if it is of type Form. This permission is only demanded if the value parameter is true and the control is not an ActiveX control. Associated enumeration: SafeTopLevelWindows value of UIPermissionWindow.
Available since 1.1