AbsolutePage-, PageCount- und PageSize-Eigenschaft (Beispiel) (VC++)

Gilt für: Access 2013, Office 2013

In diesem Beispiel werden die Eigenschaften AbsolutePage, PageCount und PageSize verwendet, um Namen und Einstellungstermine aus der Tabelle Employee anzuzeigen, und zwar fünf Datensätze gleichzeitig.

// BeginAbsolutePageCpp 
#import "C:\Program Files\Common Files\System\ADO\msado15.dll" no_namespace rename("EOF", "EndOfFile") 
 
 
#include <stdio.h> 
#include <ole2.h> 
#include "conio.h" 
#include "AbsolutepageX.h" 
 
//Function Declarations. 
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);}; 
void AbsolutePageX(void); 
void PrintProviderError(_ConnectionPtr pConnection); 
 
/////////////////////////////////////////////////////////// 
// // 
// Main Function // 
// // 
/////////////////////////////////////////////////////////// 
void main() 
{ 
 if(FAILED(::CoInitialize(NULL))) 
 return; 
 
 AbsolutePageX(); 
 
 ::CoUninitialize(); 
} 
 
 
///////////////////////////////////////////////////////////// 
// // 
// AbsolutePageX Function // 
// // 
///////////////////////////////////////////////////////////// 
 
void AbsolutePageX(void) 
{ 
 
 // Define ADO object pointers. 
 // Initialize pointers on define. 
 // These are in the ADODB:: namespace. 
 _RecordsetPtr pRstEmployees = NULL; 
 
 
 //Define Other Variables 
 //Interface Pointer declared.(VC++ Extensions) 
 IADORecordBinding *picRs = NULL; 
 CEmployeeRs emprs; //C++ class object 
 HRESULT hr = S_OK; 
 _bstr_t strMessage; 
 
 //Open a recordset using a Client Cursor 
 //For the Employee Table 
 
 _bstr_t strCnn("Provider='sqloledb';Data Source='MySqlServer';" 
 "Initial Catalog='pubs';Integrated Security='SSPI';"); 
 
 try 
 { 
 // Open a recordset. 
 TESTHR(hr = pRstEmployees.CreateInstance(__uuidof(Recordset))); 
 
 // Use client cursor to enable Absoluteposition property. 
 pRstEmployees->CursorLocation = adUseClient; 
 
 // You have to explicitly pass the default Cursor type 
 // and LockType to the Recordset here 
 TESTHR(hr = pRstEmployees->Open("employee", 
 strCnn,adOpenForwardOnly,adLockReadOnly,adCmdTable)); 
 
 //Open an IADORecordBinding interface pointer which we'll use for 
 //Binding Recordset to a class 
 TESTHR(hr = pRstEmployees->QueryInterface 
 (__uuidof(IADORecordBinding), (LPVOID*)&picRs)); 
 
 //Bind the Recordset to a C++ Class here 
 TESTHR(hr = picRs->BindToRecordset(&emprs)); 
 
 //Display Names and hire dates, five records at a time 
 pRstEmployees->PageSize = 5; 
 
 int intPageCount = pRstEmployees->PageCount; 
 
 for(int intPage=1;intPage<=intPageCount;intPage++) 
 { 
 pRstEmployees->put_AbsolutePage((enum PositionEnum)intPage); 
 strMessage = ""; 
 
 for(int intRecord=1; 
 intRecord<=pRstEmployees->PageSize;intRecord++) 
 { 
 printf("\t%s %s %.10s\n", 
 emprs.lau_fnameStatus == adFldOK ? 
 emprs.m_szau_fname : "<NULL>", 
 emprs.lau_lnameStatus == adFldOK ? 
 emprs.m_szau_lname : "<NULL>", 
 emprs.lau_hiredateStatus == adFldOK ? 
 emprs.m_szau_hiredate : "<NULL>"); 
 
 pRstEmployees->MoveNext(); 
 
 if(pRstEmployees->EndOfFile) 
 break; 
 } 
 
 printf("\n Press any key to continue...");getch(); 
 
 //Clear the Screen for the next Display 
 system("cls"); 
 } 
 } 
 catch(_com_error &e) 
 { 
 // Notify the user of errors if any. 
 _variant_t vtConnect = pRstEmployees->GetActiveConnection(); 
 
 // GetActiveConnection returns connect string if connection 
 // is not open, else returns Connection object. 
 switch(vtConnect.vt) 
 { 
 case VT_BSTR: 
 printf("Error:\n"); 
 printf("Code = %08lx\n", e.Error()); 
 printf("Message = %s\n", e.ErrorMessage()); 
 printf("Source = %s\n", (LPCSTR) e.Source()); 
 printf("Description = %s\n", (LPCSTR) e.Description()); 
 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 (pRstEmployees) 
 if (pRstEmployees->State == adStateOpen) 
 pRstEmployees->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. 
 printf("Error:\n"); 
 for(long iError = 0; iError < nCount; iError++) 
 { 
 pErr = pConnection->Errors->GetItem(iError); 
 printf("\t Error number: %x\t%s\n", pErr->Number, 
 (LPCSTR) pErr->Description); 
 } 
 } 
} 
//EndAbsolutePageCpp 

AbsolutePageX.h

 
// BeginAbsolutePageH 
#include "icrsint.h" 
 
 
//This Class extracts only fname,lastname and hire_date 
 
class CEmployeeRs : public CADORecordBinding 
{ 
BEGIN_ADO_BINDING(CEmployeeRs) 
 
 //Column fname is the 2nd field in the table 
 ADO_VARIABLE_LENGTH_ENTRY2(2, adVarChar, m_szau_fname, 
 sizeof(m_szau_fname), lau_fnameStatus, FALSE) 
 
 ADO_VARIABLE_LENGTH_ENTRY2(4, adVarChar, m_szau_lname, 
 sizeof(m_szau_lname), lau_lnameStatus, TRUE) 
 
 ADO_VARIABLE_LENGTH_ENTRY2(8, adVarChar, m_szau_hiredate, 
 sizeof(m_szau_hiredate), lau_hiredateStatus, TRUE) 
 
 
 
END_ADO_BINDING() 
 
public: 
 CHAR m_szau_lname[41]; 
 ULONG lau_lnameStatus; 
 CHAR m_szau_fname[41]; 
 ULONG lau_fnameStatus; 
 CHAR m_szau_hiredate[40]; 
 ULONG lau_hiredateStatus; 
 
}; 
// EndAbsolutePageH