title: OpenXML SDK2.5 (Excel): How to determine if a cell contains a numeric value?
body: <p>I am busy developing a component which imports data from a MS Excel (2016) file.
  This component uses the MS OpenXML SDK2.5 library. The end-users installation of MS Excel is based on Dutch country / region settings.
  The file contains, among others, a column with financial data (numeric). The position of this column is not known in advance.</p>
  
  <p>To determine if a cell contains numeric data I evaluate the property Cell.DataType (of type CellValues, which is an enum).
  At first it seems that this property is the perfect candidate to determine this. Possible values of CellValues are:
  Boolean, Number, Error, SharedString, String, InlineString or Date. So I would expect that Cell.DataType is set to CellValues.Number.
  After some debugging I found out that Cell.DataType is null when the cell contains numeric data.</p>
  
  <p>While searching on internet to find an explanation I found the following MSDN article:
  <a href="https://msdn.microsoft.com/en-us/library/office/hh298534.aspx" rel="nofollow noreferrer">https://msdn.microsoft.com/en-us/library/office/hh298534.aspx</a></p>
  
  <p>The article describes exactly what I found during debugging:</p>
  
  <blockquote>
    <p>The Cell type provides a DataType property that indicates the type of the data within the cell. The value of the DataType property is null for numeric and date types.</p>
  </blockquote>
  
  <p>Does anybody know why Cell.DataType is not initialized with respectively CellValues.Number or CellValues.Date?</p>
  
  <p>What is the best way to determine if a cell contains a numeric value?</p>