title: What is "System.Windows.Navigation" assembly in Windows Form Applications
body: <p>i am trying to add these codes :  </p>
  
  <pre><code>public partial class My_SyS : Form
  {
      List&lt;Uri&gt; HistoryStack;
      int HistoryStack_Index;
      bool fromHistory;
  
      public Sisi_Start()
      {
          InitializeComponent();
  
          HistoryStack = new List&lt;Uri&gt;();
          HistoryStack_Index = 0;
          fromHistory = false;
          webBrowser_main.Navigated += new EventHandler&lt;System.Windows.Navigation.NavigationEventArgs&gt;(webBrowser_main_Navigated);
          updateNavButtons();
      }
  
      ....
  </code></pre>
  
  <p>and here is <code>webBrowser_main_Navigated</code> event :    </p>
  
  <pre><code>private void webBrowser_main_Navigated(object sender, System.Windows.Navigation.NavigationEventArgs e)
  {
  }
  </code></pre>
  
  <p>i got the <strong>error</strong> below :   </p>
  
  <pre><code>The type or namespace name 'Navigation' does not exist in the namespace 'System.Windows' (are you missing an assembly reference?)
  </code></pre>
  
  <p>which assembly should i use for the reference?   </p>