title: FileStream.close() does not free file for other processes
body: <p>I have Following Code in a Page_Load called function. When the Page is loaded the first time after starting Visual Studio, everything works out fine.<br>
  But any other opening call to the File after that returns <code>IOException: "File is in use by another process"</code>, even when directly opening the File in VisualStudio Solution this Error is returned(of course not as Exception)</p>
  
  <pre><code>FileStream mailinglist_FileStream = new FileStream(@"\foobarFile.txt", FileMode.Open);
  PeekingStreamReader mailinglist_Reader = new PeekingStreamReader(mailinglist_FileStream);
  //Do some stuff with the file
  mailinglist_FileStream.Close();
  mailinglist_Reader.Close();
  mailinglist_Reader.Dispose();
  mailinglist_FileStream.Dispose();
  </code></pre>
  
  <p>Why is the file still locked? and why does fully restarting Visual Studio reset the File? 
  when checking file-Properties it says: </p>
  
  <blockquote>
    <p>Build Action: Content<br>
    Copy to output directory: do not Copy</p>
  </blockquote>
  
  <p>I am only reading this File. can i do something similiar to <code>adLockOptimistic</code>, so that multiple processes can access the File?</p>