When an assembly uses Windows Forms (classes and interfaces from the <code>System.Windows.Forms</code> namespace) its entry point should be marked with the <code>STAThreadAttribute</code> to indicate that the threading model should be "Single-Threaded Apartment" (STA) which is the only one supported by Windows Forms.

This rule raises an issue when the entry point (<code>Shared Sub Main</code> method) of an assembly using Windows Forms is not marked as STA.

== Noncompliant Code Example

----
Imports System.Windows.Forms

Public Class Foo
  Shared Sub Main()
    Dim winForm As Form = New Form
    Application.Run(winForm)
  End Sub
End Class
----

== Compliant Solution

----
Imports System.Windows.Forms

Public Class Foo
  <STAThread()> Shared Sub Main()
    Dim winForm As Form = New Form
    Application.Run(winForm)
  End Sub
End Class
----