<username>

                    # 最近联系的联系人

                    filehelper,xxx@chatroom,wxid_xxx,xxx,...

                </username>

                <unreadchatlist>

                    <chat>

                        <username>

                        # 朋友圈

                            MomentsUnreadMsgStatus

                        </username>

                        <lastreadtime>

                            1454502365

                        </lastreadtime>

                    </chat>

                </unreadchatlist>

                <unreadfunctionlist>

                # 未读的功能账号消息，群发助手，漂流瓶等

                </unreadfunctionlist>

            </op>

        </msg>

文本消息

MsgType: 1

    FromUserName: 发送方ID

    ToUserName: 接收方ID

    Content: 消息内容

图片消息

itchat 增加了 Text 键, 键值为下载该图片的方法.

MsgType: 3

    FromUserName: 发送方ID

    ToUserName: 接收方ID

    MsgId: 用于获取图片，用于表示每一条消息

    Content: