title: How to test if a file is fully copied in .NET
body: <p>I am monitoring a folder for new files and need to process them. The problem is that occasionally file opening fails, because system has not finished copying it.</p>
  
  <p>What is the correct way to test if the file is finished copying?</p>
  
  <p>Clarification:
  I don't have write permissions to the folder/files and cannot control the copying process (it's the user).</p>