title: Call public void from a code file in main form
body: <p>I want to call a void like this:</p>
  
  <pre><code>public void test()
  {
  // Blah blah.
  }
  
  private void button1_Click(object sender, RoutedEventArgs e)
  {
  test();
  }
  </code></pre>
  
  <p>But in this case, I want to call a public void from another .cs file in another .cs file. </p>