title: How to split a Filestream into two substreams
body: <p>Is there a way to split a filestream which is obtained via </p>
  
  <pre><code>File.Open("100GB.bin", FileMode.Open, FileAccess.Read, FileShare.Read)
  </code></pre>
  
  <p>into 2 equally sized substreams?
  I would like to upload the file partially to a website, but the webserver has limitations on the maximum filesize allowed for posting.
  Two streams are necessary to simultaneously upload the parts to the website.
  Thanks in advance.</p>