title: Check if TableLayoutPanel contains instance?
body: <p>I would like to check if a TableLayoutPanels already contains an instance of a UserControl but it don't works like this. mainActiveContr != userControl are both an instance of the AddEntryControl so shouldn't it be false? It's true ...
  Contains also seems to return true, but shouldn't it return false??</p>
  
  <pre><code>private UserControl mainActiveContr;
  
  private void IsUserControlAlreadyActive(UserControl userControl)
  {
      if (!tableLayoutPanel1.Contains(userControl) &amp;&amp; mainActiveContr != userControl)
          this.tableLayoutPanel1.Controls.Add(userControl, 3, 2);
  
  }
  </code></pre>
  
  <p>If someone clicks on of the buttons i create an instance of the UserControl and then i would like to check it.</p>
  
  <pre><code>AddEntryControl formChild1 = new AddEntryControl();
  IsUserControlAlreadyActive(formChild1);
  </code></pre>