TsgcHTTP3Client › Properties › PeerControlStreamId
Stream ID of the unidirectional control stream opened by the server.
property PeerControlStreamId: Int64 read FPeerControlStreamId;Int64
-1 until the server opens its control stream.
This property is read-only. Each HTTP/3 endpoint opens one unidirectional control stream that carries SETTINGS, GOAWAY, MAX_PUSH_ID and CANCEL_PUSH frames (RFC 9114 Section 6.2.1). This reports the ID of the stream the server opened.
It stays -1 until that stream has been identified, so a value other than -1 confirms the server control stream is up. The settings it delivered are exposed through PeerSettings.
The value is a diagnostic and tracing aid. In the .NET implementation it always returns 0 and is kept for API parity only.
if oClient.PeerControlStreamId <> -1 then
ShowMessage('server control stream is open');