title: Second path fragment must not be a drive or UNC name
body: <p>How to read all image files in folder by  environment path folder in main folder:</p>
  <pre><code>   string path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), &quot;mainFolder&quot;); 
  </code></pre>
  <p>for example if inner folder for one file path is:</p>
  <pre><code>  Bitmap bmp = new Bitmap(path + &quot;/folder/pic1.bmp&quot;);
  </code></pre>
  <p>but I want read all files of  <code>mainFolder/folder</code>:</p>
  <pre><code>pic1.bmp
  pic2.bmp
  pic3.bmp
  pic5.bmp
  </code></pre>
  <p>Not sure how to do it properly:</p>
  <pre><code>foreach (string imageFileName in Directory.GetFiles(path, &quot;/folder/*.bmp&quot;))
  {
      using (Bitmap bmp = new Bitmap(imageFileName))
      {
        // process 
      }
  }
  </code></pre>
  <p>this way I  have: <code>Second path fragment must not be a drive or UNC name</code></p>
  <p>and  this way:</p>
  <pre><code>foreach (string imgFileName in Directory.GetFiles(path + &quot;/folder/*.bmp&quot;))
  </code></pre>
  <p>I got: <code>Illegal characters in path.</code></p>