title: how to Convert Lambda expression to Func<> variable
body: <p>I have code for searching file. And now have Lambda Expression for filtering that.How to convert the Expression to <code>Func&lt;string&gt;</code> variable.
  Thanks</p>
  
  <p>Code :</p>
  
  <pre><code>Directory.GetFiles(folder, "*" + KeyWord + "*").Where(f =&gt; formatFile.Contains(f.Split('.').Last().ToLower()));
  </code></pre>
  
  <p>into variable :</p>
  
  <pre><code>Func&lt;string&gt; Lambda = ?? (f =&gt; formatFile.Contains(f.Split('.').Last().ToLower())) \\ convert the Expression;
  </code></pre>