need help importing the native DLL??

**Suzan YILDIRIM** · Jan 31 '10, 01:44 PM

i have a native or an unmanaged DLL that i will use this DLL to conrol an external device and i have tried to call it into c# but i have trouble with non-Blittable types...i have tried marshal these types but i'm not sure whether i achieved it..??

for example;

Code:

typedef struct
{
	unsigned char TagType;
	unsigned char AntNum;
	unsigned char Ids[12];
}TagIds;

/***************C# Convert**********************/

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct TagIds
        {
            public byte TagType;
            public byte AntNum;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 12)]
            string Ids;
        }

/****************C# Convert*******************/

is there any problem with this conversion??

**dennisoleksyuk** · Jan 31 '10, 04:11 PM

Can you post C header for the function that you are trying to call?

**Suzan YILDIRIM** · Jan 31 '10, 04:21 PM

Code:

__declspec(dllexport) __stdcall short DrfIsoMultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr);

and the function is used like this

Code:

     if(DrfIsoMultiTagIdentify（ComHandle，&Cnt,TagData,0Xff）==0)
     {
          for(i = 0; i < Cnt; i++)
              OutputDate(TagData[i]);
     }

**tlhintoq** · Jan 31 '10, 04:29 PM

TIP: When you are writing your question, there is a button on the tool bar that wraps the [code] tags around your copy/pasted code. It helps a bunch. Its the button with a '#' on it. More on tags. They're cool. Check'em out.

**Suzan YILDIRIM** · Jan 31 '10, 04:32 PM

TIP: When you are writing your question, there is a button on the tool bar that wraps the [code] tags around your copy/pasted code. It helps a bunch. Its the button with a '#' on it. More on tags. They're cool. Check'em out.

sorry i didn't know it.. i do

**Suzan YILDIRIM** · Jan 31 '10, 05:01 PM

and the C header file for the functions that i am trying to call is

Code:

typedef struct
{
	unsigned char TagType;
	unsigned char AntNum;
	unsigned char Ids[12];
}TagIds;
typedef short apiStatus;

apiStatus __declspec(dllexport) __stdcall DrfCommOpen (HANDLE * hCom, char *com_port);
apiStatus __declspec(dllexport) __stdcall DrfCommClose (HANDLE hCom);
apiStatus __declspec(dllexport) __stdcall DrfSetParameter (HANDLE hCom, unsigned int iRomAddr, unsigned char value,unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGetParameter (HANDLE hCom , unsigned int iRomAddr, unsigned char *value,unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfSetMultiParameter(HANDLE hCom , unsigned int iRomAddr, unsigned char ParaCount,unsigned char * Parameters, unsigned char ReaderAddr = 0xff); 
apiStatus __declspec(dllexport) __stdcall DrfGetMultiParameter(HANDLE hCom, unsigned int iRomAddr, unsigned char ParaCount,unsigned char *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfSetBaudRate(HANDLE hCom, USHORT BaudRate, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfReset (HANDLE hCom, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfSetWorkAntenna (HANDLE hCom, unsigned char Antenna, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfSetRf(HANDLE hCom,unsigned char power,unsigned char freq_type,unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGetRf(HANDLE hCom,unsigned char * power,unsigned char  *freq_type,unsigned char ReaderAddr = 0xff) ;
apiStatus __declspec(dllexport) __stdcall DrfSetAntennaCycle (HANDLE hCom, unsigned char Cycle, unsigned char ReaderAddr = 0xff) ;
apiStatus __declspec(dllexport) __stdcall DrfAntennaQuery( HANDLE hCom, unsigned char* Receive, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfSetFrequency (HANDLE hCom, unsigned char Channel, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGetFrequency (HANDLE hCom, unsigned char *Channel, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfSetPower(HANDLE hCom, USHORT Mode, UCHAR PowerLevel, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGetPower(HANDLE hCom, UCHAR *PowerLevel, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGetFirmwareVersion (HANDLE hCom, unsigned char *major,unsigned char *minor, unsigned char ReaderAddr = 0xff);

apiStatus __declspec(dllexport) __stdcall DrfIsoReadWithID(HANDLE hCom, unsigned char* TagID,unsigned char iRomAddr,unsigned char *AntNum,unsigned char* value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoWriteWithID(HANDLE hCom, unsigned char* TagID,unsigned char iRomAddr,unsigned char value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoMultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoMultiTagRead(HANDLE hCom,  unsigned char iRomAddr,unsigned int * Count,TagIds *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoWriteTag(HANDLE hCom ,unsigned char iRomAddr,unsigned char value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoBlockWrite(HANDLE hCom, unsigned char iRomAddr,unsigned char length,unsigned char* value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoLockTag(HANDLE hCom ,unsigned char iRomAddr, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfIsoQueryLock(HANDLE hCom, unsigned char iRomAddr,unsigned char *status, unsigned char ReaderAddr = 0xff);

apiStatus __declspec(dllexport) __stdcall DrfGen2SingleRead(HANDLE hCom, unsigned char MemBank,unsigned char WordCount,unsigned char *AntNum,unsigned char* value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGen2MultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGen2WriteTag(HANDLE hCom ,unsigned char iRomAddr,unsigned int value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGen2LockTag(HANDLE hCom,unsigned char MemBank = 1, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGen2KillTag(HANDLE hCom ,unsigned char PassWord, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfGen2InitTag(HANDLE hCom, unsigned char BitCount = 96, unsigned char ReaderAddr = 0xff);

apiStatus __declspec(dllexport) __stdcall DrfClass1SingleIdentify(HANDLE hCom,unsigned char * AntNum, unsigned char *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfClass1MultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall DrfClass1Program(HANDLE hCom, unsigned char * Values,unsigned char ReaderAddr = 0xff);

apiStatus __declspec(dllexport) __stdcall GetTagData(HANDLE hCom,int Count,TagIds *value, unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall ClearIDBuffer(HANDLE hCom,unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall QueryIDCount(HANDLE hCom,unsigned char* Count,unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall GetIDACK(HANDLE hCom,unsigned char ReaderAddr = 0xff);
apiStatus __declspec(dllexport) __stdcall GetId(HANDLE hCom,unsigned char *value,unsigned char ReaderAddr = 0xff);

////////////////////////////////////////////////////////////////////////////////////////////////
apiStatus __declspec(dllexport) __stdcall GetTwoID(HANDLE hCom,unsigned char *Count,unsigned char *value,unsigned char ReaderAddr = 0xff);

**dennisoleksyuk** · Jan 31 '10, 07:21 PM

I created library with the same function exposed as your RFID driver. Then I called that function from .NET.

Header that I created:

Code:

typedef struct
{
	unsigned char TagType;
	unsigned char AntNum;
	unsigned char Ids[12];
}TagIds;

typedef unsigned long HANDLE;
typedef short apiStatus;

apiStatus __declspec(dllexport) __stdcall DrfIsoMultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr = 0xff);

Implementation for the header

Code:

#include "function.h"

apiStatus __declspec(dllexport) __stdcall DrfIsoMultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr){
	*Count = 1;

	value->AntNum = 2;
	value->TagType = 3;
	for(int i=0; i<12;i++){
		value->Ids[i] = i+4;
	}

	return 0;
}

Here is .NET code that calls that function

Code:

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;

namespace RunTestDriver
{
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct TagIds
        {
            public byte TagType;
            public byte AntNum;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
            public byte[] Ids;
        }
    
    class Program
    {
        //short __declspec(dllexport) __stdcall DrfIsoMultiTagIdentify(HANDLE hCom, unsigned int * Count,TagIds *value, unsigned char ReaderAddr){

        [DllImport("TestDriver.dll", CallingConvention = CallingConvention.StdCall, EntryPoint = "?DrfIsoMultiTagIdentify@@YGFKPAIPAUTagIds@@E@Z")]
        static extern short DrfIsoMultiTagIdentify(uint hCom, ref int Count, ref TagIds value, byte ReaderAddr);

        static void Main(string[] args)
        {
            Console.WriteLine("Press enter to start");
            Console.ReadLine();

            TagIds tag = new TagIds();
            tag.Ids = new byte[12];
            int count = 0;
            Console.WriteLine(DrfIsoMultiTagIdentify(1,ref count,ref tag,1));
            Console.WriteLine(count);
            Console.WriteLine(tag.AntNum);
            Console.WriteLine(tag.TagType);
            for (int i = 0; i < 12; i++) {
                Console.WriteLine(tag.Ids[i]);
            }


            Console.WriteLine("Press enter to finish");
            Console.ReadLine();
        }
    }
}

Example code shows numbers from 0 to 15. It indicates that all structures where passed to the C++ code and back successfully.

Let us know if this solution works for you.

**Suzan YILDIRIM** · Jan 31 '10, 07:43 PM

btw i'm not the writer of this DLL..

Code:

[DllImport("TestDriver.dll", CallingConvention = CallingConvention.StdCall, EntryPoint = "?DrfIsoMultiTagIdentify@@YGFKPAIPAUTagIds@@E@Z")]

the name of the dll is DrfApiV10 so should i use this name instead of TestDriver.dll and i don't understand Implementation for the header
that you have created..can you clarify it for me please??

**dennisoleksyuk** · Jan 31 '10, 07:57 PM

I created that DLL because I don't have real dll and equipment that it uses. It just have the same convention as your DLL. You don't need to create it. I needed to check my C# code somehow.

Yes you need to put DrfApiV10.dll in place of TestDriver.dll in my example.

Whitin my C++ implementation I'm returning 0 as a result of function, assigning 1 to Count, assigning 2 to the AntNum field of tag, assigning 3 to the TagType field of tag, and then fill array within the tag with values from 4 to 15.

Then within my C# I'm printing all these fields. I can check in such a way that they were transfered correctly from C++.

**Suzan YILDIRIM** · Jan 31 '10, 08:44 PM

dennisoleksyuk,
thanks for your explanation..it 's very clear..i have tried to call my DLL into C# for months..i have seen very miscellaneous examples to marshal the function parameters..but yours is very simple..for example i have done it like

Code:

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
      public struct TagIds
      {
          public byte TagType;
          public byte AntNum;
          [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 12)]
          public string Ids; 
      }

public class LibWrap
{
 
     [DllImport("DrfApiV10.dll", CallingConvention = CallingConvention.StdCall,CharSet=CharSet.Ansi, EntryPoint = "DrfIsoMultiTagIdentify")]

     public static extern short isoMultiTagIdentify(IntPtr hCom, ref uint Count,[In,Out] TagIds[] value,byte ReaderAddr );
     public static short isoMultiTagIdentify(IntPtr hCom, ref uint Count, [In,Out] TagIds[] value)
       {
           return isoMultiTagIdentify(hCom,ref Count, value, 0xff);
       }
}

what can be said about this..??

**dennisoleksyuk** · Jan 31 '10, 09:24 PM

Please, give me more specific question.

**Suzan YILDIRIM** · Jan 31 '10, 09:44 PM

Please, give me more specific question.

sorry..it's my foolishness..th e functions that is imported has default values...like unsigned char ReaderAddr = 0xff..for this imported function, i have written an overloaded one..does the compiler give any error??

P.S. i haven't tried to communicate the RFID reader yet..before all else i have tried to figure out the DLL

**dennisoleksyuk** · Feb 2 '10, 01:16 AM

You just remove optional argument from signature in your .NET code.

Code:

[DllImport("TestDriver.dll", CallingConvention = CallingConvention.StdCall, EntryPoint = "?DrfIsoMultiTagIdentify@@YGFKPAIPAUTagIds@@E@Z")]
        static extern short DrfIsoMultiTagIdentify(uint hCom, ref int Count, ref TagIds value);

C++ library will fill missed arguments with default values.

**Suzan YILDIRIM** · Feb 2 '10, 08:39 AM

Originally posted by dennisoleksyuk

You just remove optional argument from signature in your .NET code.

Code:

[DllImport("TestDriver.dll", CallingConvention = CallingConvention.StdCall, EntryPoint = "?DrfIsoMultiTagIdentify@@YGFKPAIPAUTagIds@@E@Z")]
        static extern short DrfIsoMultiTagIdentify(uint hCom, ref int Count, ref TagIds value);

C++ library will fill missed arguments with default values.

unfortunately default parameters are not supported by C# before 4.0

need help importing the native DLL??

need help importing the native DLL??

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