title: How to merge cells in Excel?
body: <p>I have a list of objects and I am trying to dedicate <em>three</em> rows for every object and I am using the "Office Open Xml library" with this routine: </p>
  
  <pre><code>int row = 1, col = 1; 
  for (int i = 0; i &lt; MyList.Count * 3; i+=3)
  {
      MySheet.Cells[row + i, col, row + i + 1, col].Merge = true; // merge two and get a "result"
      MySheet.Cells[row + i + 1, col, row + i + 2, col].Merge = true; // merge "result" with third row
  }
  </code></pre>
  
  <p>However it pops an error saying <em>can't merge already merged cell</em>. </p>
  
  <p>So the question is <strong>How to merge <em>more than two cells</em> in Excel</strong>?</p>