title: How could I detect new window open in c# webview2
body: <p>I'm currently using webview2</p>
  <p>I used <code>this.Topmost = true;</code>because the program should always stay on Top.</p>
  <p>When using webview2, in certain sites, when the button in pressed, a new window may appear instead of changing the current window.</p>
  <p>In this case, because <code>this.Topmost = true;</code> in the current program, the newly opened window will go down.</p>
  <p>I want to put the current program on top and the newely opened window above it.</p>
  <p>Is there any way to detect the newly opened window?</p>