Occurs when joining a meeting action is finished, error code is 0 means the action succeeds, otherwise means the action is failed.
Occurs when leaving a meeting action is finished, error code is 0 means the action succeeds, otherwise means the action is failed.
Occurs when the meeting state is changed.
Occurs when joining a meeting action is finished, error code is 0 means the action succeeds, otherwise means the action is failed.