title: Check if an event already exists
body: <p>I have a data grid loading row event</p>
  
  <pre><code>_gridObj.LoadingRow += new EventHandler&lt;DataGridRowEventArgs&gt;(_gridObj_LoadingRow);
  </code></pre>
  
  <p>and in the handler I am creating another event. In the following code how can I know if the MouseLeftBtn event already exists for that row?</p>
  
  <pre><code>void _gridObj_LoadingRow(object sender, DataGridRowEventArgs e)
  {
      e.Row.MouseLeftButtonUp += new MouseButtonEventHandler(Row_MouseLeftButtonUp);
  }
  </code></pre>
  
  <p>Thanks,</p>
  
  <p>Voodoo</p>