TBuf8和unsigned char转换的初级有关问题

TBuf8和unsigned char转换的初级问题
_LIT8(KDesKey,"12345678");
TBuf8<8> deskey;
deskey.Copy(KDesKey);

unsigned char* pdata = deskey.Ptr();

最后一行始终提示：
1337483950207 illegal implicit conversion from 'const unsigned char *'
错误，
请指教，那里错了，谢谢

------解决方案--------------------------------------------------------
unsigned char* pdata = (unsigned char*)deskey.Ptr();//不让转就强转反正类型是一样的