title: Wait for Open File Dialog to Open in Selenium
body: <p>I have a Driver that clicks a Browse button on the page which opens a Open File Dialog. As of now, I am doing a <code>Thread.Sleep(2000)</code> but is there a way to figure out when the dialog has opened?</p>
  <pre><code>[Fact]
  public void UploadDoc()
  {
     UploadButton.Click();
  
     // How can I wait for the dialog to open instead of doing this?
     Thread.Sleep(2000);
  
     // Sends keys to open dialog and continues execution
  }
  </code></pre>