title: Load large amount of excel data with EPPlus
body: <p>I have a basic winforms app that a user can upload an excel file (.xlsx) and I want to read the contents of this file so I am using EPPlus.</p>
  
  <p>The problem is, I am trying to load the contents of a very large excel file, it has 7 tabs, with one tab haveing more then 200k rows, and another tab with 70k. The other 5 total to about 50k.</p>
  
  <p>These file will also only continue to get bigger.(The end goal) Since I want to import the data, read the data, and depending on the rules/data I have, I need to write data back on the excel file and export it.</p>
  
  <p>I am having issues though with EPPlus in achieving the loading of the data.</p>
  
  <p>here is code</p>
  
  <pre><code>var file = new FileInfo(filePath);
  using (var package = new ExcelPackage(file))
  {
      try
      {
          // Get the work book in the file
          ExcelWorkbook workBook = package.Workbook; //Hangs here for about 2 mins
          if (workBook != null)
          {
              if (workBook.Worksheets.Count &gt; 0)
              {
                  // Get the first worksheet
                  ExcelWorksheet currentWorksheet = workBook.Worksheets.First();
                  // gets the currentWorksheet but doesn't evaluate anything...
  
              }
          }
      }
      catch (Exception ex)
      {
          throw ex;
      }
  }
  </code></pre>
  
  <p>The code hangs on  the package.workbook line for roughly 2 minutes. Then it gets down into the if where it gets the currentWorkSheet, and if I look at the contents of that variable in my watch, nothing is really loaded since it displays: </p>
  
  <p><strong>Function evaluation disabled because a previous function evaluation timed out. You must continue execution to reenable function evaluation.</strong></p>
  
  <p>I looked at this <a href="http://epplus.codeplex.com/wikipage?title=FAQ&amp;referringTitle=Documentation" rel="nofollow">link</a> from EPPlus and it shows the only issue with loading large files is load from top to bottom and left to right, and they are saying more than 5,000. I have way more than though so I am just wondering if this could even be possible with EPPlus?</p>
  
  <p>Additionally, I have did some google searching and most issues are they can't open the large excel files on server where they could locally...</p>
  
  <p>I have also started looking at Open XML SDK and it seems to be better performance wise, but also much more difficult to use code wise.</p>