{aka 'int (::)(esp_mqtt_event_t*)'} to type 'mqtt_event_callback_t' {aka 'int (*)(esp_mqtt_event_t*)'}

Question

When i trying to build the code got error

error: cannot convert 'MQTTManager::mqtt_event_handler' from type 'esp_err_t (MQTTManager::)(esp_mqtt_event_handle_t)' {aka 'int (MQTTManager::)(esp_mqtt_event_t*)'} to type 'mqtt_event_callback_t' {aka 'int (*)(esp_mqtt_event_t*)'}

i try put a MQTT manager to a class, then i use the event handle to

esp_mqtt_client_config_t.event_handle

here is the mqttmanage.h

class MQTTManager
{
public:
    void begin();

private:
    esp_mqtt_client_config_t mqttCfg;    // MQTT
    esp_mqtt_client_handle_t mqttClient; // MQTT

    esp_err_t mqtt_event_handler(esp_mqtt_event_handle_t event);
}

and here is the mqtt.cpp

esp_err_t MQTTManager::mqtt_event_handler (esp_mqtt_event_handle_t event)
{
......
}

void MQTTManager::begin()
{
    Serial.println("---MQTT INITIALIZATION---");
    mqttCfg.host = MQTT_HOST;
    mqttCfg.port = MQTT_PORT;
    mqttCfg.keepalive = 60;
    mqttCfg.username = MQTT_USERNAME;
    mqttCfg.password = MQTT_PASSWORD;
    mqttCfg.event_handle = mqtt_event_handler;
    mqttCfg.lwt_topic = topicPubStatus;
    mqttCfg.lwt_msg = "0";
    mqttCfg.lwt_msg_len = 1;
    mqttCfg.lwt_retain = 1;
.....
}

what should i do ?

Learn Class and Making some device prototype