在您需要使用QNIMSDK功能的类中，import 相关头文件。
您在使用QNIMSDK所有功能之前，您必须先调用此方法初始化 SDK。 在 App 的整个生命周期中，您只需要将 SDK 初始化一次。

// 设置存储路径

NSString* dataDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject stringByAppendingPathComponent:@“ChatData”];

NSString* cacheDir = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).firstObject stringByAppendingString:@“UserCache”];

// 初始化

QNSDKConfig *config = [[QNSDKConfig alloc] initConfigWithDataDir:dataDir cacheDir:cacheDir pushCertName:@“Your APNS Certification” userAgent:@“userAgent”];

config.appID = @“Your AppID”;

[[QNIMClient sharedClient] registerWithSDKConfig:config];

 [[QNIMClient sharedClient] signInByName:im_username password:im_password completion:^(QNIMError * _Nonnull error) {
  }];

// groupID：聊天室ID  message：加入聊天室验证消息（可不传）
- (void)joinGroupWithGroupId:(NSString *)groupId
          message:(NSString *)message
       completion:(void(^)(QNIMError *error))aCompletionBlock;

//forceRefresh 如果设置了forceRefresh则从服务器拉取
- (void)getGroupInfoByGroupId:(long long)groupId
                 forceRefresh:(BOOL)forceRefresh
                   completion:(void(^)(QNIMGroup *group,
                                       QNIMError *error))aCompletionBlock;

[[QNIMGroupOption sharedOption] leaveGroupWithGroupId:self.groupId completion:^(QNIMError * _Nonnull error) {
     
}];

[[QNIMGroupOption sharedOption] addDelegate:self];

/**
 退出了某群
 */
- (void)groupLeft:(QNIMGroup *)group reason:(NSString *)reason{

}

/**
 * 加入新成员
 **/
- (void)groupMemberJoined:(QNIMGroup *)group
                 memberId:(NSInteger)memberId
                  inviter:(NSInteger)inviter{

}

/**
 * 群成员退出
 **/
- (void)groupMemberLeft:(QNIMGroup *)group
               memberId:(NSInteger)memberId
                reason:(NSString *)reason{

}

 /**
 创建文本消息

 @param content 内容
 @param fromId 发送id
 @param toId 接收id
 @param mtype 消息类型
 @param conversationId 会话id
 @return QNIMMessageObject
 */
- (instancetype)initWithQNIMMessageText:(NSString *)content
                                fromId:(long long )fromId
                                  toId:(long long)toId
                                  type:(QNIMMessageType)mtype
                        conversationId:(long long )conversationId;

QNIMMessageObject *messageModel = [[QNIMMessageObject alloc]initWithQNIMMessageText:@"加入了房间" fromId:imUserId.longLongValue toId:self.groupId.longLongValue type:QNIMMessageTypeGroup conversationId:self.groupId.longLongValue];
[[QNIMChatOption sharedOption] sendMessage:messageModel];

//添加监听者
[[QNIMChatOption sharedOption] addDelegate:self];

//收到消息
 - (void)receivedMessages:(NSArray<QNIMMessageObject *> *)messages {
    
}

//  消息状态发生变化
  - (void)messageStatusChanged:(QNIMMessageObject *)message error:(QNIMError *)error {
    
}