CPU卡与传统的MifareOne系列卡相比，具有更加安全、复杂的认证机制，这就意味着CPU卡的读写操作在软件开发中变得更加的复杂。我们这些复杂的操作封装成5个通用的函数，与我们的CPU读写器相结合，让您十分钟就搞定CPU的读写操作。

       //'CPU卡寻卡及将卡复位到14443A-4的指令状态
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpurequest")]
        static extern byte cpurequest(byte[] serial, byte[] param, byte[] cosver, byte[] code);
        //-----------------------------------------------------------------------------------------------------------------------------
        //初始化函数，(ctrlword是否需要先清空卡,不需要清空的话，可以需输入卡密码，卡密码长度)ctrlword_0是否先清空卡，分配空间（字节数），
        //Public Declare Function cpursinit Lib "OUR_MIFARE.dll" (ByVal ctrlword As Byte, ByVal key As Long, ByVal keylen As Byte, ByVal customsize As Long) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpursinit", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpursinit(byte ctrlword, byte[] key, byte[] keylen, Int32 customsize);
        //-----------------------------------------------------------------------------------------------------------------------------
        //增加文件（文件序号0~5，文件只读密码：长度,文件读写密码,长度，分配空间)
        //Public Declare Function cpursfileadd Lib "OUR_MIFARE.dll" (ByVal fileno As Byte, ByVal readonlykey As Long, ByVal readonlykeylen As Byte, ByVal writekey As Long, ByVal writekeylen As Byte, ByVal customsize As Long) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpursfileadd", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpursfileadd(byte fileno, byte[] readonlykey, byte[] readonlykeylen, byte[] writekey, byte[] writekeylen, Int32 customsize);
        //-----------------------------------------------------------------------------------------------------------------------------
        //'修改文件密码，修改后，请妥慎记住，否则该文件将无法再用
        //Public Declare Function cpursfilekeychg Lib "OUR_MIFARE.dll" (ByVal fileno As Byte, ByVal keytype As Byte, ByVal oldkey As Long, ByVal oldkeylen As Byte, ByVal newkey As Long, ByVal newkeylen As Byte) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpursfilekeychg", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpursfilekeychg(byte fileno, byte keytype, byte[] oldkey, byte[] oldkeylen, byte[] newkey, byte[] newkeylen);
        //-----------------------------------------------------------------------------------------------------------------------------
        //'修改卡密码，卡密码和文件没有任何关系，卡密码只是用来清空卡，读和写文件是无效的。
        //Public Declare Function cpurscardkeychg Lib "OUR_MIFARE.dll" (ByVal oldkey As Long, ByVal oldkeylen As Byte, ByVal newkey As Long, ByVal newkeylen As Byte) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpurscardkeychg", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpurscardkeychg(byte fileno, byte[] readonlykey, byte[] readonlykeylen, byte[] writekey, byte[] writekeylen, Int32 customsize);
        //-----------------------------------------------------------------------------------------------------------------------------

        //读文件数据(文件序号,读写密码,密码长度,读取起始位置,读取长度,读出内容)
        //Public Declare Function cpursfiledataread Lib "OUR_MIFARE.dll" (ByVal fileno As Byte, ByVal keytype As Byte, ByVal key As Long, ByVal keylen As Byte, ByVal startaddr As Long, ByVal databuf As Long, ByVal datalen As Long) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpursfiledataread", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpursfiledataread(byte fileno, byte keytype, byte[] rwkey, byte[] rwkeylen, Int32 startaddr, byte[] databuf, Int32 datalen);
        //-----------------------------------------------------------------------------------------------------------------------------
        //写文件数据(文件序号,文件读写密码,密码长度,写入起始位置,写入长度，写入内容)
        //Public Declare Function cpursfiledatawrite Lib "OUR_MIFARE.dll" (ByVal fileno As Byte, ByVal keytype As Byte, ByVal key As Long, ByVal keylen As Byte, ByVal startaddr As Long, ByVal databuf As Long, ByVal datalen As Long) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpursfiledatawrite", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpursfiledatawrite(byte fileno, byte keytype, byte[] rwkey, byte[] rwkeylen, Int32 startaddr, byte[] databuf, Int32 datalen);
        //-----------------------------------------------------------------------------------------------------------------------------
        //修改卡密码，卡密码和文件没有任何关系，卡密码只是用来清空卡，读和写文件是无效的。
        //Public Declare Function cpurscardkeychg Lib "OUR_MIFARE.dll" (ByVal oldkey As Long, ByVal oldkeylen As Byte, ByVal newkey As Long, ByVal newkeylen As Byte) As Byte
        [DllImport("OUR_MIFARE.dll", EntryPoint = "cpurscardkeychg", CallingConvention = CallingConvention.StdCall)]
        static extern byte cpurscardkeychg(byte[] oldkey, byte[] oldlen, byte[] newkey, byte[] newlen);