MQTT Protocol
Lightweight publish-subscribe messaging protocol designed for IoT and constrained devices. Full support for MQTT 3.1.1 and MQTT 5.0 specifications.
Lightweight publish-subscribe messaging protocol designed for IoT and constrained devices. Full support for MQTT 3.1.1 and MQTT 5.0 specifications.
Lightweight publish-subscribe messaging for IoT and constrained devices. Full MQTT 3.1.1 and MQTT 5.0 support, over WebSocket or raw TCP.
TsgcWSPClient_MQTT
Windows, macOS, Linux, iOS, Android
Standard / Professional / Enterprise
Pair a TsgcWebSocketClient with TsgcWSPClient_MQTT, wire OnMQTTConnect / OnMQTTPublish, then Subscribe and Publish.
uses
sgcWebSocket, sgcWebSocket_Protocol_MQTT_Client,
sgcWebSocket_Protocol_MQTT_Message;
var
WSClient: TsgcWebSocketClient;
MQTT: TsgcWSPClient_MQTT;
begin
WSClient := TsgcWebSocketClient.Create(nil);
WSClient.Host := 'www.esegece.com';
WSClient.Port := 15675;
MQTT := TsgcWSPClient_MQTT.Create(nil);
MQTT.Client := WSClient;
MQTT.Authentication.Enabled := True;
MQTT.Authentication.UserName := 'sgc';
MQTT.Authentication.Password := 'sgc';
MQTT.OnMQTTConnect := MQTTConnect;
MQTT.OnMQTTPublish := MQTTPublish;
WSClient.Active := True;
end;
procedure TForm1.MQTTConnect(Connection: TsgcWSConnection;
const Session: Boolean; const ReasonCode: Integer;
const ReasonName: string;
const ConnectProperties: TsgcWSMQTTCONNACKProperties);
begin
MQTT.Subscribe('sensors/temperature/#');
end;
procedure TForm1.MQTTPublish(Connection: TsgcWSConnection;
aTopic, aText: string;
PublishProperties: TsgcWSMQTTPublishProperties);
begin
Memo1.Lines.Add(aTopic + ': ' + aText);
end;
// Publish a retained QoS 1 message
MQTT.Publish('sensors/temperature/room1',
'{"value":22.5,"unit":"C"}', mtqsAtLeastOnce, True);// uses: sgcWebSocket, sgcWebSocket_Protocol_MQTT_Client
TsgcWebSocketClient *WSClient = new TsgcWebSocketClient(this);
WSClient->Host = "www.esegece.com";
WSClient->Port = 15675;
TsgcWSPClient_MQTT *MQTT = new TsgcWSPClient_MQTT(this);
MQTT->Client = WSClient;
MQTT->Authentication->Enabled = true;
MQTT->Authentication->UserName = "sgc";
MQTT->Authentication->Password = "sgc";
MQTT->OnMQTTConnect = MQTTConnect;
MQTT->OnMQTTPublish = MQTTPublish;
WSClient->Active = true;
void __fastcall TForm1::MQTTPublish(TsgcWSConnection *Connection,
UnicodeString aTopic, UnicodeString aText,
TsgcWSMQTTPublishProperties PublishProperties)
{
Memo1->Lines->Add(aTopic + ": " + aText);
}
MQTT->Publish("sensors/temperature/room1",
"{\"value\":22.5,\"unit\":\"C\"}", mtqsAtLeastOnce, true);using esegece.sgcWebSockets;
var WSClient = new TsgcWebSocketClient();
WSClient.Options.Parameters = "/ws";
var MQTT = new TsgcWSPClient_MQTT();
MQTT.Client = WSClient;
MQTT.Authentication.Enabled = true;
MQTT.Authentication.UserName = "sgc";
MQTT.Authentication.Password = "sgc";
MQTT.HeartBeat.Enabled = true;
MQTT.HeartBeat.Interval = 5;
MQTT.OnMQTTConnect += (conn, session, code, name, props) => MQTT.Subscribe("sensors/temperature/#");
MQTT.OnMQTTPublish += (conn, topic, text, props) => Console.WriteLine(topic + ": " + text);
WSClient.Host = "www.esegece.com";
WSClient.Port = 15675;
WSClient.Active = true;
MQTT.Publish("sensors/temperature/room1",
"{\"value\":22.5,\"unit\":\"C\"}", TmqttQoS.mtqsAtLeastOnce, true);10 published properties, 9 methods and 13 events — matched against the TsgcWSPClient_MQTT reference.
MQTTVersion selects the level advertised in the CONNECT packet — MQTT 3.1.1 or MQTT 5.0. ConnectProperties carries the MQTT 5 session-expiry, receive-maximum, packet-size, topic-alias and extended-auth fields.
Plug the Client property into a TsgcWebSocketClient to run MQTT over WebSockets, or into a TsgcWSMQTTBroker via Broker to use the native TCP transport on port 1883/8883.
Publish at QoS 0, 1 or 2 with optional retain. QoS property controls default level, retry interval and timeout. PublishAndWait blocks until the broker acknowledges — useful for transactional publishes.
LastWillTestament registers the topic, payload, QoS and retain flag the broker will publish on this client's behalf if the connection drops ungracefully — a clean way to signal device disconnects.
Subscribe / UnSubscribe accept topic filters with + and # wildcards. OnMQTTPublish delivers incoming messages; OnMQTTPublishEx gives raw bytes / stream. Full QoS 2 handshake exposed via OnMQTTPubRec, OnMQTTPubRel, OnMQTTPubComp.
HeartBeat sends PINGREQ on a timer and detects silent broker drops. Authentication sends a UserName/Password in CONNECT. MQTT 5 enhanced auth: call Auth and handle OnMQTTAuth for SCRAM-style challenges.
Authoritative sources for the protocols this component implements.
Przejdź bezpośrednio do dokumentacji komponentu, pobierz gotowy do uruchomienia projekt demonstracyjny i pobierz wersję próbną.
| Pomoc online — Protocol_MQTT Pełna dokumentacja właściwości, metod i zdarzeń tego komponentu. | Otwórz | |
| Projekt demonstracyjny — Demos\Protocols\MQTT Gotowy do uruchomienia projekt przykładowy. Dostarczany w pakiecie sgcWebSockets — pobierz wersję próbną poniżej. | Otwórz | |
| Dokument techniczny (PDF) Features, quick start, code samples for Delphi, C++ Builder and .NET and primary-source references — this component only. | Otwórz | |
| Podręcznik użytkownika (PDF) Kompleksowy podręcznik obejmujący każdy komponent biblioteki. | Otwórz |