mapxdataset.cpp

mapx程序的源代码

					else {
						dTmp = 0.0;
					}
					SafeArrayPutElement(psa, &nCount, &dTmp);
					break;
				}
				case VT_BSTR: {
					CString strVal;
					if( strColumnName.CompareNoCase("StateAbbr") == 0 ){
						strVal = aachStateAbbr[iRows];
					}
					else if( strColumnName.CompareNoCase("TOTPOPHIS") == 0 ){
						strVal="";
					}
					else if( strColumnName.CompareNoCase("TOTPOPCUR") == 0 ){
						strVal="";
					}
					else if( strColumnName.CompareNoCase("TOTPOPPRO") == 0 ){
						strVal="";
					}
					else {
						strVal="";
					}
					BSTR bstrVal = strVal.AllocSysString();
					SafeArrayPutElement(psa, &nCount, bstrVal);
					break;
				}
				default:
					// Shouldn't ever happen
					break;
			}
		}
	}
	catch (...) {
		*pNumRecordsFetched = -1;
		if( psa!=NULL ) {
			SafeArrayDestroy(psa);
		}

		return E_FAIL;
	}

	pvarData->vt = vtRequested | VT_ARRAY;
	pvarData->parray = psa;
	*pNumRecordsFetched = nCount;
	return S_OK;
}

// IMMapXStaticDataset interface
// TODO:  Implement the routines in this interface.
// See IMMapXStaticDataset Interface specification for details.
STDMETHODIMP CMapXSampleDataset::BeginFetch()
{
  return S_OK;
}

STDMETHODIMP CMapXSampleDataset::EndFetch()
{
  return S_OK;
}

STDMETHODIMP CMapXSampleDataset::FetchData(long lColNum, long lIdxRow, VARTYPE vtRequested, VARIANT* pvarData, BOOL * pbNoMoreData)
{
	HRESULT hrRet = S_OK;

	if ( lIdxRow > (sizeof(aachStateAbbr) / sizeof(aachStateAbbr[0]) ) ){
		*pbNoMoreData = TRUE;
		return hrRet;
	}

	try {

		IMMapXColumnInfo* pIMMapXColumnInfo;
		HRESULT hr = GetColumnInfoByIndex( lColNum, &pIMMapXColumnInfo);
		if( FAILED(hr) ) throw hr;
		CComBSTR bstrColumnName;
		hr = pIMMapXColumnInfo->GetName(&bstrColumnName);
		if( FAILED(hr) ) throw hr;
		pIMMapXColumnInfo->Release();
		CString strColumnName = bstrColumnName;

		switch (vtRequested) {
			// TODO: we cheat here because we know that currently MapX
			// will ask for only doubles or BSTR's.  You shouldn't.
			case VT_R8: {
				double dTmp;
				if( strColumnName.CompareNoCase("StateAbbr") == 0 ){
					dTmp = 0.0;
				}
				else if( strColumnName.CompareNoCase("TOTPOPHIS") == 0 ){
					dTmp = alTOTPOPHIS[lIdxRow];
				}
				else if( strColumnName.CompareNoCase("TOTPOPCUR") == 0 ){
					dTmp = alTOTPOPCUR[lIdxRow];
				}
				else if( strColumnName.CompareNoCase("TOTPOPPRO") == 0 ){
					dTmp = alTOTPOPPRO[lIdxRow];
				}
				else {
					dTmp = 0.0;
				}
				pvarData->vt = VT_R8;
				pvarData->dblVal = dTmp;
				break;
			}
			case VT_BSTR: {	
				CString strVal;
				if( strColumnName.CompareNoCase("StateAbbr") == 0 ){
					strVal = aachStateAbbr[lIdxRow];
				}
				else if( strColumnName.CompareNoCase("TOTPOPHIS") == 0 ){
					strVal.Format("%d",alTOTPOPHIS[lIdxRow]);
				}
				else if( strColumnName.CompareNoCase("TOTPOPCUR") == 0 ){
					strVal.Format("%d",alTOTPOPCUR[lIdxRow]);
				}
				else if( strColumnName.CompareNoCase("TOTPOPPRO") == 0 ){
					strVal.Format("%d",alTOTPOPPRO[lIdxRow]);
				}
				else {
					strVal = "";
				}
				pvarData->vt = VT_BSTR;
				pvarData->bstrVal = strVal.AllocSysString();
				break;
			}
			default:
				// Shouldn't ever happen
				break;
		}
	}
	catch( HRESULT hrThrown ) {
		hrRet = hrThrown;
	}
	return hrRet;
}



#define MAX_KEY_LEN 3
long KeyToRow(CString& strKey) 
{
	// This could (obviously) be much more efficient
	char* pchKey = strKey.GetBuffer(MAX_KEY_LEN);
	long lIdx = 0;
	long lRetVal = -1;

	while( lIdx <= sizeof(aachStateAbbr) / sizeof(aachStateAbbr[0]) ) {
		if( strnicmp( pchKey, aachStateAbbr[lIdx], 2 ) == 0 ) {
			lRetVal = lIdx;
			break;
		}
		lIdx++;
	}
	strKey.ReleaseBuffer();
	return lRetVal;
}


// IMMapXDynamicDataset
// TODO:  Implement the routines in this interface.
// See IMMapXDynamicDataset Interface specification for details.
STDMETHODIMP CMapXSampleDataset::FetchData(long lColNum, long lKeyColNum, BSTR bstrKey, long lRefineColNum, BSTR bstrRefiningKey, VARTYPE vtRequested, VARIANT *pvarData)
{
	HRESULT hrRet = S_OK;
	CString strKey = bstrKey;

	try {
		IMMapXColumnInfo* pIMMapXColumnInfo;
		HRESULT hr = GetColumnInfoByIndex( lKeyColNum, &pIMMapXColumnInfo);
		if( FAILED(hr) ) throw hr;
		CComBSTR bstrKeyColumnName;
		hr = pIMMapXColumnInfo->GetName(&bstrKeyColumnName);
		if( FAILED(hr) ) throw hr;
		pIMMapXColumnInfo->Release();
		CString strKeyColumnName = bstrKeyColumnName;
		if( strKeyColumnName.CompareNoCase("StateAbbr") != 0 ) {
			throw E_FAIL;			
		}

		long lIdxRow = KeyToRow(strKey);
		if( lIdxRow == -1 ) {
			throw E_FAIL;
		}

		hr = GetColumnInfoByIndex( lColNum, &pIMMapXColumnInfo);
		if( FAILED(hr) ) throw hr;
		CComBSTR bstrColumnName;
		hr = pIMMapXColumnInfo->GetName(&bstrColumnName);
		if( FAILED(hr) ) throw hr;
		pIMMapXColumnInfo->Release();
		CString strColumnName = bstrColumnName;

		switch (vtRequested) {
			// TODO: we cheat here because we know that currently MapX
			// will ask for only doubles or BSTR's.  You shouldn't.
			case VT_R8: {
				double dTmp;
				if( strColumnName.CompareNoCase("StateAbbr") == 0 ){
					dTmp = 0.0;
				}
				else if( strColumnName.CompareNoCase("TOTPOPHIS") == 0 ){
					dTmp = alTOTPOPHIS[lIdxRow];
				}
				else if( strColumnName.CompareNoCase("TOTPOPCUR") == 0 ){
					dTmp = alTOTPOPCUR[lIdxRow];
				}
				else if( strColumnName.CompareNoCase("TOTPOPPRO") == 0 ){
					dTmp = alTOTPOPPRO[lIdxRow];
				}
				else {
					dTmp = 0.0;
				}
				pvarData->vt = VT_R8;
				pvarData->dblVal = dTmp;
				break;
			}
			case VT_BSTR: {	
				CString strVal;
				if( strColumnName.CompareNoCase("StateAbbr") == 0 ){
					strVal = aachStateAbbr[lIdxRow];
				}
				else if( strColumnName.CompareNoCase("TOTPOPHIS") == 0 ){
					strVal.Format("%d",alTOTPOPHIS[lIdxRow]);
				}
				else if( strColumnName.CompareNoCase("TOTPOPCUR") == 0 ){
					strVal.Format("%d",alTOTPOPCUR[lIdxRow]);
				}
				else if( strColumnName.CompareNoCase("TOTPOPPRO") == 0 ){
					strVal.Format("%d",alTOTPOPPRO[lIdxRow]);
				}
				else {
					strVal = "";
				}
				pvarData->vt = VT_BSTR;
				pvarData->bstrVal = strVal.AllocSysString();
				break;
			}
			default:
				// Shouldn't ever happen
				break;
		}
	}
	catch( HRESULT hrThrown ) {
		hrRet = hrThrown;
	}
	return hrRet;
}

// IMMapXColumnInfoContainer interface
// The implementation of this interface is pretty standard.  We provide the following
// implementation.  Use it if you wish, or replace it with your own optimized/customized
// implementation if appropriate.
STDMETHODIMP CMapXSampleDataset::GetColumnInfoByName(BSTR bstrColumnName, IMMapXColumnInfo** ppIMMapXColumnInfo)
{
	HRESULT hrRet = S_OK;
	*ppIMMapXColumnInfo = NULL;
	try {
		if (!cols || !m_lCols) throw E_FAIL;
		for (long l = 0; l < m_lCols; l++) {
			CComBSTR bstr;
			HRESULT hRes = (cols[l])->GetName(&bstr);
			if( FAILED(hRes) ) throw hRes;
			if( wcscmp(bstr, bstrColumnName) == 0) {
				// found a match
				*ppIMMapXColumnInfo = cols[l];
				(*ppIMMapXColumnInfo)->AddRef();
				hrRet = S_OK;
				break;
			}
		}
	}
	catch(HRESULT hrThrown) {
		hrRet = hrThrown;
	}

	return hrRet;
}

STDMETHODIMP CMapXSampleDataset::GetColumnInfoByIndex(long lIndex, IMMapXColumnInfo** ppIMMapXColumnInfo)
{
	HRESULT hrRet = S_OK;
	*ppIMMapXColumnInfo = NULL;
	try {
		if (!cols || !m_lCols) throw E_FAIL;
		for (long l = 0; l < m_lCols; l++) {
			long lColumnNumber;
			HRESULT hr = (cols[l])->GetColumnNumber(&lColumnNumber);
			if( FAILED(hr) ) return E_FAIL;
			if (lColumnNumber == lIndex) {
				*ppIMMapXColumnInfo = cols[l];
				(*ppIMMapXColumnInfo)->AddRef();
				break;
			}
		}
	}
	catch(HRESULT hrThrown) {
		hrRet = hrThrown;
	}

	return hrRet;
}

STDMETHODIMP CMapXSampleDataset::GetColumnInfoEnumerator(IMEnumMapXColumnInfo** ppIMEnumMapXColumnInfo)
{
	CComObject<CMEnumMapXColumnInfo> *penum = NULL;
	try {
		penum=new CComObject<CMEnumMapXColumnInfo>;
		if( !penum ) throw E_OUTOFMEMORY;
		// We need to give the enumerator object our unknown so it can reference count us.
		// It needs to reference count us because we own the IMMapXColumnInfo*s that it is
		// enumerating
		// We want ATL to make it's own copy of the IMMapXColumnInfo*'s in our array for the
		// enumerator object.
		HRESULT hr = penum->Init(&cols[0], &cols[m_lCols], GetUnknown(), AtlFlagCopy);
		if( FAILED(hr) ) {
			throw hr;
		}
	}
	catch (HRESULT hrThrown) {
		if( penum ) delete penum;
		return hrThrown;
	}
	catch(...) {
		if( penum ) delete penum;
		return E_FAIL;
	}
	// NOTE:  Nothing below here can throw an exception.

	// If the enumerator were created by CoCreateInstance(), our ClassFactory
	// would call FinalConstruct().  But it wasn抰, so call it explicitly.
	penum->InternalFinalConstructAddRef();
	HRESULT hr = penum->FinalConstruct();
	penum->InternalFinalConstructRelease();
	if (SUCCEEDED(hr)) {
		hr = penum->QueryInterface(IID_IMEnumMapXColumnInfo, reinterpret_cast<void**>(ppIMEnumMapXColumnInfo));
	}
	if (FAILED(hr)) {
		delete penum;
	}
	return hr;
}