Пример использования метода Move (VC++)

Область применения: Access 2013, Office 2013

В этом примере с помощью метода Move указатель перемещается в соответствии с вводимыми пользователем данными.

 
// BeginMoveCpp 
#import "C:\Program Files\Common Files\System\ADO\msado15.dll" no_namespace rename("EOF", "EndOfFile") 
 
#include <stdio.h> 
#include <ole2.h> 
#include <stdlib.h> 
#include <conio.h> 
#include "MoveX.h" 
 
// Function Declaration. 
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);}; 
void MoveX(void); 
void PrintProviderError(_ConnectionPtr pConnection); 
void PrintComError(_com_error &e); 
inline char* mygets(char* strDest, int n) 
{ 
 char strExBuff[10]; 
 char* pstrRet = fgets(strDest, n, stdin); 
 
 if (pstrRet == NULL) 
 return NULL; 
 
 if (!strrchr(strDest, '\n')) 
 // Exhaust the input buffer. 
 do 
 { 
 fgets(strExBuff, sizeof(strExBuff), stdin); 
 }while (!strrchr(strExBuff, '\n')); 
 else 
 // Replace '\n' with '\0' 
 strDest[strrchr(strDest, '\n') - strDest] = '\0'; 
 
 return pstrRet; 
} 
 
/////////////////////////////////////////////////////////// 
// // 
// Main Function // 
// // 
/////////////////////////////////////////////////////////// 
void main() 
{ 
 if(FAILED(::CoInitialize(NULL))) 
 return; 
 
 MoveX(); 
 
 ::CoUninitialize(); 
} 
 
////////////////////////////////////////////////// 
// // 
// MoveX Function // 
// // 
////////////////////////////////////////////////// 
 
void MoveX(void) 
{ 
 // Define ADO object pointers. 
 // Initialize pointers on define. 
 // These are in the ADODB:: namespace. 
 _RecordsetPtr pRstAuthors = NULL; 
 
 // Define Other Variables 
 IADORecordBinding *picRs = NULL; //Interface Pointer declared 
 CAuthorsRs authorsrs; //C++ class object 
 HRESULT hr = S_OK; 
 
 // Open Authors table 
 _bstr_t strCnn("Provider='sqloledb';Data Source='MySqlServer';" 
 "Initial Catalog='pubs';Integrated Security='SSPI';"); 
 
 try 
 { 
 // Open recordset from Authors table. 
 TESTHR(pRstAuthors.CreateInstance(__uuidof(Recordset))); 
 
 pRstAuthors->CursorType = adOpenStatic; 
 // Use client cursor to allow use of AbsolutePosition property. 
 pRstAuthors->CursorLocation = adUseClient; 
 
 pRstAuthors->Open("SELECT au_id, au_fname, au_lname, city, " 
 "state FROM Authors ORDER BY au_lname", strCnn, adOpenStatic, 
 adLockReadOnly, adCmdText); 
 
 // Open an IADORecordBinding interface pointer which we'll use 
 // for Binding Recordset to a class. 
 TESTHR(pRstAuthors->QueryInterface( 
 __uuidof(IADORecordBinding),(LPVOID*)&picRs)); 
 
 // Bind the Recordset to a C++ Class here. 
 TESTHR(picRs->BindToRecordset(&authorsrs)); 
 
 pRstAuthors->MoveFirst(); 
 
 char *strMove; 
 char strTemp[5]; 
 while(true) 
 { 
 // Display information about current record and ask how many 
 // records to move. 
 printf("Record %ld of %d\n", pRstAuthors->AbsolutePosition, 
 pRstAuthors->RecordCount); 
 printf("Author: %s %s\n", 
 authorsrs.lemp_fnameStatus == adFldOK ? 
 authorsrs.m_au_fname : "<NULL>", 
 authorsrs.lemp_lnameStatus == adFldOK ? 
 authorsrs.m_au_lname : "<NULL>"); 
 printf("Location: %s, %s\n\n", 
 authorsrs.lemp_cityStatus == adFldOK ? 
 authorsrs.m_au_city : "<NULL>", 
 authorsrs.lemp_stateStatus == adFldOK ? 
 authorsrs.m_au_state : "<NULL>"); 
 
 printf("Enter number of records to Move " 
 "\n(positive or negative, Enter to quit): "); 
 mygets(strTemp, 5); 
 
 strMove = strtok(strTemp," \t"); 
 
 if (strMove == NULL) 
 break; 
 
 // if the input is not numeric then notify the user. 
 if(!atol(strMove)) 
 { 
 printf("Expecting numeric value...\n"); 
 continue; 
 } 
 
 // Store bookmark in case the Move goes too far 
 // forward or backward. 
 _variant_t varBookmark = pRstAuthors->Bookmark; 
 
 // Move method requires parameter of data type Long. 
 long lngMove = atol(strMove); 
 
 pRstAuthors->Move(lngMove); 
 
 // Trap for BOF or EOF. 
 if(pRstAuthors->BOF) 
 { 
 printf("Too far backward! Returning to current" 
 " record.\n"); 
 pRstAuthors->Bookmark = varBookmark; 
 } 
 
 if(pRstAuthors->EndOfFile) 
 { 
 printf("Too far forward! Returning to current" 
 " record.\n"); 
 pRstAuthors->Bookmark = varBookmark; 
 } 
 } 
 } 
 catch(_com_error &e) 
 { 
 // Notify the user of errors if any. 
 // Pass a connection pointer accessed from the Recordset. 
 _variant_t vtConnect = pRstAuthors->GetActiveConnection(); 
 
 // GetActiveConnection returns connect string if connection 
 // is not open, else returns Connection object. 
 switch(vtConnect.vt) 
 { 
 case VT_BSTR: 
 PrintComError(e); 
 break; 
 case VT_DISPATCH: 
 PrintProviderError(vtConnect); 
 break; 
 default: 
 printf("Errors occured."); 
 break; 
 } 
 } 
 
 // Clean up objects before exit. 
 //Release the IADORecordset Interface here 
 if (picRs) 
 picRs->Release(); 
 
 if (pRstAuthors) 
 if (pRstAuthors->State == adStateOpen) 
 pRstAuthors->Close(); 
} 
 
/////////////////////////////////////////////////////////// 
// // 
// PrintProviderError Function // 
// // 
/////////////////////////////////////////////////////////// 
 
void PrintProviderError(_ConnectionPtr pConnection) 
{ 
 // Print Provider Errors from Connection object. 
 // pErr is a record object in the Connection's Error collection. 
 ErrorPtr pErr = NULL; 
 
 if( (pConnection->Errors->Count) > 0) 
 { 
 long nCount = pConnection->Errors->Count; 
 // Collection ranges from 0 to nCount -1. 
 for(long i = 0; i < nCount; i++) 
 { 
 pErr = pConnection->Errors->GetItem(i); 
 printf("\t Error number: %x\t%s", pErr->Number, 
 (LPCSTR) pErr->Description); 
 } 
 } 
} 
 
/////////////////////////////////////////////////////////// 
// // 
// PrintComError Function // 
// // 
/////////////////////////////////////////////////////////// 
 
void PrintComError(_com_error &e) 
{ 
 _bstr_t bstrSource(e.Source()); 
 _bstr_t bstrDescription(e.Description()); 
 
 // Print Com errors. 
 printf("Error\n"); 
 printf("\tCode = %08lx\n", e.Error()); 
 printf("\tCode meaning = %s\n", e.ErrorMessage()); 
 printf("\tSource = %s\n", (LPCSTR) bstrSource); 
 printf("\tDescription = %s\n", (LPCSTR) bstrDescription); 
} 
// EndMoveCpp 

MoveX.h

// BeginMoveH 
 
#include "icrsint.h" 
 
 
// This Class extracts fname, lname, city and state 
// from the "authors" table. 
 
class CAuthorsRs : public CADORecordBinding 
{ 
BEGIN_ADO_BINDING(CAuthorsRs) 
 
 // Column au_id is the 1st field in the recordset 
 
 ADO_VARIABLE_LENGTH_ENTRY2(2, adVarChar, m_au_fname, 
 sizeof(m_au_fname), lemp_fnameStatus, TRUE) 
 
 ADO_VARIABLE_LENGTH_ENTRY2(3, adVarChar, m_au_lname, 
 sizeof(m_au_lname), lemp_lnameStatus, TRUE) 
 
 ADO_VARIABLE_LENGTH_ENTRY2(4, adVarChar, m_au_city, 
 sizeof(m_au_city), lemp_cityStatus, TRUE) 
 
 ADO_VARIABLE_LENGTH_ENTRY2(5, adChar, m_au_state, 
 sizeof(m_au_state), lemp_stateStatus, TRUE) 
 
END_ADO_BINDING() 
 
public: 
 char m_au_fname[21]; 
 ULONG lemp_fnameStatus; 
 char m_au_lname[41]; 
 ULONG lemp_lnameStatus; 
 char m_au_city[21]; 
 ULONG lemp_cityStatus; 
 char m_au_state[3]; 
 ULONG lemp_stateStatus; 
}; 
 
// EndMoveH