反向加载历史消息

String conversationID = "si_user_a_user_b";
int count = 20;

OpenIMClient.getInstance().messageManager.getAdvancedHistoryMessageListReverse(
    new OnBase<AdvancedMessage>() {
        @Override
        public void onSuccess(AdvancedMessage result) {
            List<Message> messages = result.getMessageList();
            boolean reachedLatest = result.isEnd();
            // 按 clientMsgID 去重后，将 messages 添加到当前列表后方
        }

        @Override
        public void onError(int code, String error) {
            // 处理加载失败
        }
    },
    conversationID,
    startMessage,
    count,
    ViewType.History
);