errorhandling.cpp

vc ADO 连接数据库

#include <eh.h>         // Required for Win32 Exception Handling
#include <stdio.h>      // Optional, specific to this sample
#include <afxwin.h>     // Required for MFC Exception Handling
#include <afxdisp.h>    // Required for MFC Exception Handling        

#import  <msado15.dll> rename("EOF", "adoEOF")

struct InitOle {
InitOle()  { ::CoInitialize(NULL); }
~InitOle() { ::CoUninitialize();   }
} _init_InitOle_;



// Class for Win32 Structured Exception Handling
class SEH_Exception {
private:
    unsigned int m_uSECode;
public:
    SEH_Exception(unsigned int uSECode) : m_uSECode(uSECode) {}
    SEH_Exception() {}
    ~SEH_Exception() {}
    unsigned int getSeHNumber() { return m_uSECode; }
};

// Raise Win32 Exception within a C++ Class SEH_Exception
static void MappingSEHtoCPPExceptions
(
    unsigned int uExceptionCode, 
    _EXCEPTION_POINTERS*
)
{
    throw SEH_Exception( uExceptionCode );
}

// Sets up mapping between Win32 SEH & C++ Exception Handling
void LogEnable()
{
    _set_se_translator(MappingSEHtoCPPExceptions);
}

void main( void )
{

    try
    {
        ADODB::_ConnectionPtr  Conn1 = NULL;
        Conn1.CreateInstance( __uuidof( ADODB::Connection ) );

        LogEnable();

        // To see each of the catch blocks work, comment out all but
        // one of the following 4 lines, each of which throws an
        // exception.

        // Bogus DataSource Name, raises _com_error
        Conn1->Open( L"", L"", L"", -1 );

        // Explicitly raise MFC Exception
        AfxThrowMemoryException();

        // Explicitly raise SEH Excetption
        RaiseException(EXCEPTION_ACCESS_VIOLATION, 0, 0, NULL);

        // Explicitly raise exception of a type not caught below
        // i.e. to the catch handlers, an "Unknown exception"
        throw 0L;   // Raises exception of type long


    }
    // Catch Blocks -- All of which are a subset of the 
    //                 Exception Handling demonstrated in LOG.CPP
    //                 in the C++ Rosetta Stone Samples
    catch( CException *e )
    {
        CString         strName;  
        CRuntimeClass   *pClass = e->GetRuntimeClass();

        printf( "MFC Exception(%s) thrown\n",
               (LPCTSTR) pClass->m_lpszClassName );
    }
    catch( _com_error &e )
    {
        printf( "#import encountered failed HRESULT\n" );
        printf( "\tCode = %08lx\n",      e.Error());
    }
    catch( SEH_Exception &e )
    {
        printf( "Win32 Structured Exception Raised\n" );
        printf( "\t Error Code %08lx\n", e.getSeHNumber() );
    }
    catch(...)
    {
        printf( "Caught an exception of unknown type\n" );
    }

    ::MessageBox( NULL, "Success!", "", MB_OK );
}