In relation to the recent session list, SDK maintains and provides the interface for querying and monitoring changes. As long as there is any chat with a user or team ( sends or receives messages), SDK will automatically update the recent session list and notify the upper level, and the developer is not required to manually update the session list.

Recent session SessionInfo , aka session list or recent contact list, contains the contact information of recent sessions, including contact account, contact type, time of the latest message, message status, message content, number of unread messages, etc.

SessionInfoDescription of key parameters:

Parameter Type	SessionInfo field	Description
String	Id	ID of recent contact (friend ID, team ID, etc.)
NIMSessionType	SessionType	Session type (team session, p2p message)
int	UnreadCount	Unread count of the current session
NIMSessionCommand	Command	Change operation type of the current session (add, update, delete, etc., see NIMSessionCommand for details)
String	MsgId	The unique Id of the latest message in the current session
String	Sender	Sender ID of the latest message in the current session
long	TimeTag	Timestamp of the latest message in the current session (milliseconds)
NIMMessageType	MsgType	Type of the latest message (including text, image, video, audio, etc. See NIMMessageType for details)
String	Content	Content of the latest message in the current session
String	Attach	Attachment content of the latest message in the current session
object	Attachment	Attachment content of the recent message in current session, parsed from the field Attach
NIMMsgLogStatus	Status	Status of the latest message in the current session (read, unread, etc., see Message status for details)
NIMMsgLogSubStatus	SubStatus)	Sub-status of the latest message in the current session (played, unplayed, etc., see Message sub-status for details)
bool	IsLast	In batch message notification, whether it is the last change information when the message is changed or added
bool	IsPinnedOnTop	Whether to stick the session on top (not supported for now)
bool	IsRobot	Whether it is a robot message (not supported for now)
String	ExtendString	Local extension field, limited to 4096 in length (not supported for now)

NIMSessionTypeEnumeration value description:

Enumeration	Value	Description
kNIMSessionTypeP2P	0	Individual session, i.e. p2p session
kNIMSessionTypeTeam	1	Team session

NIMSessionCommandEnumeration value description:

Enumeration	Value	Description
kNIMSessionCommandAdd	0	Add session items
kNIMSessionCommandRemove	1	Delete a single session item
kNIMSessionCommandRemoveAll	2	Delete all session items
kNIMSessionCommandRemoveAllP2P	3	Delete all p2p session items
kNIMSessionCommandRemoveAllTeam	4	Delete all team session items
kNIMSessionCommandMsgDeleted	5	Deleted messages of a single session item
kNIMSessionCommandAllMsgDeleted	6	Deleted messages of all session items
kNIMSessionCommandAllP2PMsgDeleted	7	Deleted messages of all p2p session items
kNIMSessionCommandAllTeamMsgDeleted	8	Deleted messages of all team session items
kNIMSessionCommandUpdate	9	Update session item

Note: Recent session is a local session with no roaming. Roaming is related to messages, not to recent session. In the latest version, when multiple terminals log in at the same time and clear session interfaceis called, the same session will be set to 0 on other terminals as well.

Get recent session list

Get recent session list.

• API prototype

public static void QueryAllRecentSession(QueryRecentHandler handler);

• Parameter Description

Parameter	Description
handler	Asynchronous callback function for notification query results

• Example

 NIM.Session.SessionAPI.QueryAllRecentSession((a, b) =>
    {
        if (b == null || b.SessionList == null) return;
        foreach (var item in b.SessionList)
        {
            ···
        }
    });

Monitor the change of recent session

While sending and receiving messages, SDK will update the contact information of the other party in the chat. When a message is sent or received, the SDK will send out a notification regarding the latest contact update, and you can monitor the session item change by registering the event

• API prototype

public static EventHandler<SessionChangedEventArgs> RecentSessionChangedHandler;

Description for the parameter SessionChangedEventArgs:

Parameter Type	The field SessionChangedEventArgs	Description
ResponseCode	ResCode	Error code (seeResponseCodefor details)
SessionInfo	Info	For session information, see SessionInfo
int	TotalUnreadCount	Sum of unread counts in all sessions

• Example

void OnRecentSessionChangedHandler(object sender,SessionChangedEventArgs args)
{
    if (args != null)
    {
    	...
    }
}
//Monitor event notification
SessionAPI.RecentSessionChangedHandler += OnRecentSessionChangedHandler;

//If it is no longer needed, cancel monitoring of the event
SessionAPI.RecentSessionChangedHandler -= OnRecentSessionChangedHandler;

Reset unread count

To clear the unread count of the current session, callSetUnreadCountZerointerface to do the configuration, in earlier versions, after callingSetUnreadCountZerointerface, you also need to call MarkMessagesStatusReadinterface to configure the read status of message database.

• API prototype

public static void SetUnreadCountZero(Session.NIMSessionType toType, string id, SessionChangeHandler handler)

• Parameter Description

Parameter	Description
toType	Session type
id	Session id (receiver account or group id)
handler	Asynchronous notification callback

• Example

//Specify the session type and session id for setting to read;

NIMSessionType sessionType = NIMSessionType.kNIMSessionTypeP2P;
string sessionId = "test1";

//Set clearing unread count of the session
NIM.Session.SessionAPI.SetUnreadCountZero(sessionType, sessionId, (a, b, c) =>
{
    ···
});

//Invoking the interface NIM.Messagelog.MessagelogAPI.MarkMessagesStatusRead is not required for the latest version.
NIM.Messagelog.MessagelogAPI.MarkMessagesStatusRead(sessionId, sessionType, (a, b, c) =>
{
    ···
});

Delete specified recent contact

Both local database and server will realize synchronization when deleting a session option!

• API prototype

public static void DeleteRecentSession(Session.NIMSessionType toType, string id, SessionChangeHandler handler)

• Parameter Description

Parameter	Description
toType	Session type
id	ID of recent contact (friend ID, team ID, etc.)
handler	Callback function of current operation

• Example

NIMSessionType toType = NIMSessionType.kNIMSessionTypeP2P; //Personal session
string id = "test_account";//Session id
NIM.Session.SessionAPI.DeleteRecentSession(toType, id, (a, b, c) =>
{
    ···
});

Delete all recent contacts

Delete all session list items without setting the message database to read status. If you need to update the read status of the message database at the same time, please use the delete all history interface

• API prototype

public static void DeleteAllRecentSession(SessionChangeHandler handler)

• Example

java
SessionAPI.DeleteAllRecentSession((rescode, result, totalUnreadCounts)=>
{
	...
});