This property specifies HTTP headers added to the default headers. It must follow the syntax of HTTP headers.

For example, you may add the cookies from a response to a request under some authentication (e.g. ASP.NET Forms) where a session ID is returned for subsequent requests so re-authentication is not needed. See the NoCookie property for further information if you specify cookies in the HTTP headers.

The following example shows how this property may be used.

[C#]
Doc doc = new Doc();
string url = ...;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.CookieContainer = new CookieContainer(); // required for HttpWebResponse.Cookies
request.Credentials = ...;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
if(response.Cookies.Count>0) { // includes ASP.NET_SessionId
  bool needsCookie2 = false;
  StringBuilder builder = new StringBuilder("Cookie: ");
  for(int i = 0; i<response.Cookies.Count; ++i) {
    Cookie cookie = response.Cookies[i];
    if(!needsCookie2 && cookie.Version!=1)
      needsCookie2 = true;
    if(i>0)
      builder.Append("; ");
    builder.Append(cookie.ToString());
  }
  builder.Append(!needsCookie2? "\r\n": "\r\nCookie2: $Version=1\r\n");
  doc.HtmlOptions.HttpAdditionalHeaders = builder.ToString();
}
doc.HtmlOptions.NoCookie = true;
doc.HtmlOptions.HostWebBrowser = false;
// cookieless Forms Authentication adds authentication ticket to the URL
int id = doc.AddImageUrl(response.ResponseUri.AbsoluteUri);
doc.Save(Server.MapPath("HttpHeaders.pdf"));
doc.Clear();
[Visual Basic]
Dim doc As Doc = New Doc()
Dim url As String = ...
Dim request As HttpWebRequest = CType(WebRequest.Create(url), HttpWebRequest)
request.CookieContainer = New CookieContainer() ' required for HttpWebResponse.Cookies
request.Credentials = ...
Dim response As HttpWebResponse = CType(request.GetResponse(), HttpWebResponse)
If response.Cookies.Count > 0 Then ' includes ASP.NET_SessionId
  Dim needsCookie2 As Boolean = False
  Dim builder As StringBuilder = New StringBuilder("Cookie: ")
  For i As Integer = 0 To response.Cookies.Count - 1
    Dim cookie As Cookie = response.Cookies(i)
    If Not needsCookie2 AndAlso cookie.Version <> 1 Then
      needsCookie2 = True
    End If
    If i > 0 Then builder.Append("; ")
    builder.Append(cookie.ToString())
  Next
  If Not needsCookie2 Then
    builder.Append(ControlChars.CrLf)
  Else
    builder.Append(ControlChars.CrLf & "Cookie2: $Version=1" & ControlChars.CrLf)
  End If
  doc.HtmlOptions.HttpAdditionalHeaders = builder.ToString()
End If
doc.HtmlOptions.NoCookie = True
doc.HtmlOptions.HostWebBrowser = False
' cookieless Forms Authentication adds authentication ticket to the URL
Dim id As Integer = doc.AddImageUrl(response.ResponseUri.AbsoluteUri)
doc.Save(Server.MapPath("HttpHeaders.pdf"))
doc.Clear()