Equivalent pinvoke code in C#

[gudguy]

Anyone kind enough to flex their brain muscles on creating a PInvoke signature for the following C++ codes to C#:

1.
typedef void (CALLBACK *Image_CALLBACK)(DWORD UserParam, BYTE* buf, DWORD len, DWORD dwWidth, DWORD dwHeight);

ImageCallback( HANDLE h, DWORD UserParam, Image_CALLBACK fnImageCallback );

2.
typedef struct structural_MEDIA_PORT_INFO
{
unsigned long PORT_Register;
unsigned long PORT_Control;
} MEDIA_PORT_INFO;

DLL_API bool GetPortInfoByHttp( HANDLE h, MEDIA_PORT_INFO* mri, char* HTTPIP, unsigned long HTTPPort, char* UID, char* PWD, unsigned int ChannelNO = 0 );
DLL_API void KSendURLCommand( HANDLE h, char* URLCommand, DWORD dwLen, char* ResultBuffer, DWORD& ResultBufferLen );

3.
#ifndef __AVC_UNIFICATION_SDK
#define __AVC_UNIFICATION_SDK

#define DLL_API extern "C" __declspec(dllexport)

THANKS!

gudguy