delphi - 任何人都可以帮助我解释我在尝试使用 dll 打开端口时遇到的这个错误

Question

任何人都可以帮助我解释我在尝试使用 dll 打开端口时遇到的这个错误。当我调用 SAAT_Open(myCharPtrOpen) 时，出现错误:“地址 0003D078 处的访问冲突”。不确定我是否在单元 UntRFIDAPI 上正确定义了句柄。变量 PHandle 定义正确吗？这是我的代码:

procedure TForm5.Button1Click(Sender: TObject);
 var
   myString, myString2  : string;
   myCharPtrInit: PChar;
   myCharPtrOpen: PChar;
   i : Integer;
   Open, Init: Boolean;
 begin
  // Create a string of Char's
  myString  := '&hp';
  // Point to the first character in the string
  i := 1;
  myCharPtrInit := Addr(myString[i]);
  if SAAT_TCPInit(myCharPtrInit,'192.168.3.238',7086) = True then
  begin
    StatusBar1.Panels[0].Text := 'Initiated'; //ShowMessage('Initiated');
    myString2 := 'hp';
    myCharPtrOpen := Addr(myString2[i]);
    if SAAT_Open(myCharPtrOpen) = True then StatusBar1.Panels[1].Text := 'Opened';   
  end;
end;


unit UntRFIDAPI;

INTERFACE
uses
  SysUtils, Windows, Messages, Classes, Graphics, Controls, Dialogs,
  StdCtrls, Forms, DBCtrls, DB, Grids, DBGrids,Mask, ExtCtrls,
  Buttons, WinTypes;

var
  A: String;

function SAAT_TCPInit(pHandle: Pointer; pHostName: String; nsocketPort: Integer):Boolean; stdcall;
function SAAT_Open(pHandle: Pointer):Boolean; stdcall;
function SAAT_Close(pHandle: Pointer):Boolean; stdcall;

implementation

function SAAT_TCPInit;  external 'RFIDAPI.dll';
function SAAT_Open;  external 'RFIDAPI.dll';
function SAAT_Close;  external 'RFIDAPI.dll';

end.

这是 API 调用:

1.1 初始化网口(TCP)连接

//TCP parameters initialization 
//Functionality：import by parameter, initialize TCP to prepare for opening connection
//Parameters： 
//  pHandle for preserving the opening ports handl 
//  pHostName reader IP address, only effective under the ethernet communication 
//  nsocketPort network SOCKET port 
//Returned value：true: Operation Succeeded, false Operation Failed 

bool SAAT_TCPInit (void** pHandle,char *pHostName,int nsocketPort)

如果连接读写器的IP为192.168.0.238，端口为7086，则调用如下:

HANDLE hp; 
if (!SAAT_TCPInit(&hp, ”192.168.0.238”, 7086)) 
{ 
    printf("reader initialization failed!\n"); 
    return false; 
}

Answer 1

正如 Rudy 和 David 所指出的，您对 SAAT_TCPInit() 函数签名的翻译是错误的，您对这个 API 的指针句柄的使用也是错误的。他们已经解释了为什么你的代码是错误的，所以我不再重复原因。不过，他们的答案存在一些小问题。

您的 Delphi 代码应该看起来更像这样:

unit UntRFIDAPI;

interface

function SAAT_TCPInit(out pHandle: Pointer; pHostName: PAnsiChar; nsocketPort: Integer): Boolean; stdcall;
function SAAT_Open(pHandle: Pointer): Boolean; stdcall;
function SAAT_Close(pHandle: Pointer): Boolean; stdcall;

implementation

const
  RFIDAPIDLL = 'RFIDAPI.dll';

function SAAT_TCPInit; external RFIDAPIDLL;
function SAAT_Open; external RFIDAPIDLL;
function SAAT_Close; external RFIDAPIDLL;

end.

procedure TForm5.Button1Click(Sender: TObject);
var
  hp: Pointer;
begin
  if SAAT_TCPInit(hp, '192.168.3.238', 7086) then
  begin
    StatusBar1.Panels[0].Text := 'Initiated';
    if SAAT_Open(hp) then
      StatusBar1.Panels[1].Text := 'Opened';   
    ...
    SAAT_Close(hp);
  end;
end;

作为引用，这里是 DLL 的 RFIDAPIEXPORT.h 的内容C++ 的头文件:

/***********************************************************************
* Module:  RFIDEXPORT.h
* Author:  
* Modified: 
* Purpose: 
***********************************************************************/
#pragma once

#ifndef  _RFIDEXPORT_H
#define  _RFIDEXPORT_H

#ifdef RFIDAPI_EXPORTS
#define RFID_API __declspec( dllexport )
#else
#define RFID_API __declspec( dllimport )
#endif


extern "C"
{
    bool RFID_API __stdcall SAAT_TCPInit(void** pHandle,char *pHostName,int nsocketPort);

    bool RFID_API __stdcall SAAT_COMInit(void** pHandle,unsigned char nBusAddr,char *pComNum,int nBaud );

    bool RFID_API __stdcall SAAT_USBInit(void** pHandle,unsigned char nBusAddr,char * pUSBNum,int nBaud );

    bool RFID_API __stdcall SAAT_UDPInit(void** pHandle,char *pHostName,int nsocketPort);

    bool RFID_API  __stdcall SAAT_Open(void* pHandle);

    bool RFID_API  __stdcall SAAT_Close(void *pHandle);

    bool RFID_API  __stdcall SAAT_Reconnect(void *pHandle);

    bool RFID_API  __stdcall SAAT_HeartSend (void* pHandle);

    bool RFID_API  __stdcall SAAT_SysInfSet (void* pHandle ,unsigned char nType,unsigned char* pParm,int nLen);

    bool RFID_API  __stdcall SAAT_SysInfQuery (void* pHandle ,unsigned char nType, unsigned char *pPara, unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_WorkModeSet (void* pHandle ,unsigned char nType);

    bool RFID_API  __stdcall SAAT_ParmOp (void* pHandle ,unsigned char nType, unsigned char nStartAddrr, unsigned char nLen,  unsigned char *pData, unsigned char *pDataLen);

    bool RFID_API  __stdcall SAAT_RFParaSet (void* pHandle ,unsigned char nType, unsigned char nParaLen,unsigned char* pPara);

    bool RFID_API  __stdcall SAAT_RFParaQuery (void* pHandle ,unsigned char nType,unsigned char* pPara, unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_CommunicatParaSet (void* pHandle ,unsigned char nType, unsigned char* pPara, unsigned char nLen);

    bool RFID_API  __stdcall SAAT_CommunicatParaQuery (void* pHandle ,unsigned char nType, unsigned char* pPara,unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_NetParaSet (void* pHandle ,unsigned char nType, unsigned char* pPara, unsigned char nLen);

    bool RFID_API  __stdcall SAAT_NetParaQuery (void* pHandle ,int nType, unsigned char* pPara,unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_TagOpParaSet(void* pHandle ,unsigned char nType, unsigned char *pPara,unsigned char nLen);

    bool RFID_API  __stdcall SAAT_TagOpParaQuery (void* pHandle ,unsigned char nType, unsigned char* pPara, unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_ExtendBroadParaSet (void* pHandle ,unsigned char nType, unsigned char pSendChunnel);

    bool RFID_API  __stdcall SAAT_ExtendBroadParaQuery (void* pHandle ,unsigned char nType, char* pPara, unsigned char* pLen);

    bool RFID_API  __stdcall SAAT_TotalAntennaParmQuery (void* pHandle,unsigned char *szAntennaPara,unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_AntennaParmQuery (void* pHandle,unsigned char nAntenna,unsigned char * pAntennaEnable,unsigned char *pAntennaPower,unsigned char *pAntennaQueryTime );

    bool  RFID_API  __stdcall SAAT_AntennaParmSet(void* pHandle ,unsigned char *pPara,unsigned char nLen );

    bool RFID_API  __stdcall SAAT_SetAntennaPortEnable (void* pHandle,unsigned char nAntenna,unsigned char nEnable );

    bool RFID_API  __stdcall SAAT_SetAntennaPower (void* pHandle,unsigned char nAntenna,unsigned char nPower );

    bool RFID_API  __stdcall SAAT_SetAntennaTime (void* pHandle,unsigned char nAntenna,unsigned char nTime );

    bool RFID_API  __stdcall SAAT_PowerOff(void *pHandle);

    bool RFID_API  __stdcall SAAT_CarrierWaveOp(void* pHandle ,unsigned char nType, unsigned char  nPort);

    bool RFID_API  __stdcall SAAT_IOOperate(void* pHandle,unsigned char nPort,unsigned char nState);

    bool RFID_API  __stdcall SAAT_IOStateQuery(void* pHandle,unsigned char *pState);

    bool RFID_API  __stdcall SAAT_Reboot (void* pHandle,unsigned char nMode);

    bool RFID_API  __stdcall SAAT_Reading_IOConfig (void* pHandle,unsigned char nConfigBit);

    bool RFID_API  __stdcall SAAT_Reading_IOQuery (void* pHandle,unsigned char* pConfigBit);

    bool RFID_API  __stdcall SAAT_IOPulseWidthSet (void* pHandle,unsigned char nIOPort,unsigned char nWidth);

    bool RFID_API  __stdcall SAAT_IOPulseWidthQuery (void* pHandle,unsigned char nIOPort,unsigned char* pWidth);

    bool RFID_API  __stdcall  SAAT_6BTagSelect ( void* pHandle, unsigned char nType, unsigned char nStartAddr,
                                            unsigned char nDataBite, unsigned char * Data );

    bool RFID_API  __stdcall  SAAT_6BReadUIDCode (void *pHandle,unsigned char nAntenna,unsigned char nType);

    int  RFID_API  __stdcall SAAT_6BRevUIDMsg (void *pHandle, unsigned char* nAntenna, unsigned char* pUIDData,
        unsigned char* nUIDLen);

    bool RFID_API  __stdcall SAAT_6BReadUserData ( void *pHandle ,unsigned char nAntenna,unsigned char nType,unsigned char * pTagID,unsigned char nStartAddr,unsigned char nReadLen, unsigned char *pdata,unsigned char dataLen);

    bool RFID_API  __stdcall SAAT_6BWriteUserData (void* pHandle,
        unsigned char nAntenna,
        unsigned char nType, 
        unsigned char *pTagID,
        unsigned char nStartAddr,
        unsigned char *pValue, 
        unsigned char *pLen);

    bool RFID_API  __stdcall SAAT_6BTagLock (void* pHandle, unsigned char nAntenna, unsigned char nType,
        unsigned char *pTagID, unsigned char nStartAddrr,  unsigned char nLen);

    bool RFID_API  __stdcall SAAT_6BTagLockQuery (void* pHandle, unsigned char nAntenna, 
        unsigned char *pTagID, unsigned char nStartAddr,  unsigned char nLen,unsigned char *pData,unsigned char nDataLen);

    bool RFID_API  __stdcall SAAT_6CTagSelect (  void *pHandle, unsigned char nBank ,unsigned short nStartAddr,unsigned char MaskBit, 
        unsigned char *Data ,unsigned char Datalength,unsigned char nSessionZone,
        unsigned char nActiveFlag, unsigned char nCutFlag );

    bool RFID_API  __stdcall SAAT_6CReadEPCCode ( void *pHandle,unsigned char nAntenna, unsigned char nType,
        unsigned int nTagCount);

    int  RFID_API  __stdcall SAAT_6CRevEPCMsg (void *pHandle, unsigned char* nAntenna, unsigned char* pEPCData,
        unsigned char* nEPCLen);

    bool RFID_API  __stdcall  SAAT_6CReadTIDCode ( void *pHandle,unsigned char nAntenna, unsigned char nType, unsigned int nTagCount);

    int  RFID_API  __stdcall SAAT_6CRevTIDMsg (void *pHandle, unsigned char* nAntenna, unsigned char* pTIDData, unsigned char* nTIDLen);

    bool RFID_API  __stdcall  SAAT_6CWriteEPCCode ( void* pHandle,unsigned char nAntenna,unsigned char nType,
        unsigned char *pAccessPWD, unsigned char *pWriteData,unsigned char nLen );

    bool RFID_API  __stdcall SAAT_6CReadUserData ( void* pHandle, 
        unsigned char nAntenna, 
        unsigned int StartAddr,
        unsigned int nToReadLen,
        unsigned int nWaitTime,
        unsigned char * UserData,
        unsigned int* pDataLen);

    bool RFID_API  __stdcall SAAT_6CWriteUserData (void* pHandle,  
        unsigned char nAntenna, 
        unsigned char nType,  
        unsigned char *pAccessPWD,
        unsigned int  nStartAddr,
        unsigned int nWaitTime,
        unsigned char *pWriteData, 
        unsigned int *pToWriteLen);

    bool RFID_API  __stdcall SAAT_6CWriteBankData (void* pHandle, unsigned char nAntenna, unsigned char nType, unsigned char *pAccessPWD,
        unsigned char nBank,  unsigned char *pWriteData, unsigned char nLen);

    bool RFID_API  __stdcall SAAT_6CClearBankData (void* pHandle, unsigned char nAntenna, unsigned char nType, unsigned char *pAccessPWD,
        unsigned char nBank, unsigned char nStartAddr, unsigned char nLen);

    bool RFID_API  __stdcall SAAT_6CAccessPWDSet (void *pHandle, unsigned char nAntenna, unsigned char nType, unsigned char *pOrgPWD, 
        unsigned char *pNewPWD);

    bool RFID_API  __stdcall SAAT_6CDestroyPWDSet (void *pHandle, unsigned char nAntenna,unsigned char nType, unsigned char *pAccessPWD, 
        unsigned char *pDestroyPWD );

    bool RFID_API  __stdcall  SAAT_6CTagLock (void *pHandle, unsigned char nAntenna, unsigned char *pAccessPWD, unsigned char nType,
        unsigned char nBank);

    bool RFID_API  __stdcall SAAT_6CTagKill (void *pHandle, unsigned char nAntenna,unsigned char *pDestroyPWD,
        unsigned char *pEPC, int nEPCLen);

    bool RFID_API  __stdcall SAAT_6CEASFlagSet (void *pHandle, unsigned char nAntenna, unsigned char nType,
        unsigned char* pAccessPwd,  int nEASFlag);

    bool  RFID_API  __stdcall SAAT_6CEASMonitorEnable (void *pHandle, unsigned char nAntenna,unsigned char nSetEAS);

    bool RFID_API __stdcall SAAT_Copyright(void** pHandle, char* copyright);

    bool RFID_API  __stdcall SAAT_SetLanguageType (void* pHandle,char* szType);

    bool RFID_API  __stdcall SAAT_GetErrorMessage(void *pHandle,char *szMsg, int nLen);

    bool RFID_API  __stdcall SAAT_GetErrorCode(void *pHandle,int *pCode);

    bool RFID_API  __stdcall SAAT_SysTest(void* pHandle ,unsigned char nType,unsigned char nAntenna, unsigned char *pTestParm, unsigned char nLen);

    bool RFID_API  __stdcall SAAT_RawSendData(void* pHandle , unsigned char *pSendData, unsigned char nLen);

    bool RFID_API  __stdcall SAAT_RawRevData(void* pHandle , unsigned char *pRecvData, unsigned char* pLen,int nWaitTime); 

    bool RFID_API  __stdcall SAAT_RawSendAndRevData(void* pHandle , 
        unsigned char *pSendData,
        unsigned char nLen,
        unsigned char *pRecvData,
        unsigned char *pLen,
        unsigned char nWaitTime); 

    bool RFID_API __stdcall SAAT_EnterTrans(void* pHandle ,unsigned char nType);

    bool RFID_API __stdcall SAAT_ResetWifiBaund(void* pHandle);
};
#endif

这里是 DLL 文档的链接:

API Calling Quick StartSAAT-800 Series Reader .