WPF WebView2でのKeyDownの取得

function initialize() {
    window.addEventListener("keydown", handleKeydown);

    function handleKeydown(event) {
        var keyCode = event.keyCode;
        // Enter key
        if (keyCode == 13) {
            window.chrome.webview.postMessage("Enter Key Down");
        }
    }
}
 

private async void Window_Loaded(object sender, RoutedEventArgs e)
{
    await webView.EnsureCoreWebView2Async(null);
    webView.CoreWebView2.WebMessageReceived += GetMessage;
}

private void GetMessage(object sender, CoreWebView2WebMessageReceivedEventArgs e)
{
    if (e.TryGetWebMessageAsString() == "Enter Key Down")
    {
        textBox.Focus();
        textBox.SelectAll();
    }
}