C# 调用 C++ DLL 函数声明问题

[wade008]

C++中的函数定义如下

typedef enum
{
RESULT_INITIALIZE = -1,
RESULT_SUCCESS = 0, // Operation was successful
RESULT_ERR_BADFILENAME,
RESULT_ERR_BADPORT
}Result_t;

typedef enum
{
HHP_COM1=0,
HHP_COM2,
HHP_COM3,
HHP_LAST_COMM_PORT = 255,
HHP_COM_AUTO = HHP_LAST_COMM_PORT
}HHP_CONNECT_TYPE;

Result_t hhpConnect( HHP_CONNECT_TYPE connectType=HHP_COM_AUTO, const void* pStruct=NULL );


转成C#,要怎么声明？