simplepointdatasethelper.cpp

COM编程接口处理方法 多个方法调用COM库函数

// SimplePointDatasetHelper.cpp : Implementation of CSimplePointDatasetHelper
#include "stdafx.h"
#include "SimplePointVC.h"
#include "SimplePointDatasetHelper.h"
#include "GeneralUtils.h"

/////////////////////////////////////////////////////////////////////////////
// CSimplePointDatasetHelper

STDMETHODIMP CSimplePointDatasetHelper::InterfaceSupportsErrorInfo(REFIID riid)
{
	static const IID* arr[] = 
	{
		&IID_ISimplePointDatasetHelper
	};
	for (int i=0; i < sizeof(arr) / sizeof(arr[0]); i++)
	{
		if (InlineIsEqualGUID(*arr[i],riid))
			return S_OK;
	}
	return S_FALSE;
}

// IPlugInDatasetInfo
STDMETHODIMP CSimplePointDatasetHelper::get_LocalDatasetName(BSTR *localName)
{
	if (! localName) return E_POINTER;
  
	return m_sDatasetName.CopyTo(localName);
}

STDMETHODIMP CSimplePointDatasetHelper::get_DatasetType(esriDatasetType *DatasetType)
{
	if (! DatasetType) return E_POINTER;
  
	*DatasetType = esriDTFeatureClass;
	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_GeometryType(esriGeometryType *GeometryType)
{
	if (! GeometryType) return E_POINTER;
  
	*GeometryType = esriGeometryPoint;
	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_ShapeFieldName(BSTR *ShapeFieldName)
{
	if (! ShapeFieldName) return E_POINTER;

	CComBSTR str(L"Shape");
	*ShapeFieldName = str.Detach();
	return S_OK;
}

// IPlugInDatasetHelper
STDMETHODIMP CSimplePointDatasetHelper::get_ClassCount(long *Count)
{
	if (! Count) return E_POINTER;

	// This is a standalone feature class
  *Count = 1;

	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_ClassName(long Index, BSTR *Name)
{
	if (! Name) return E_POINTER;

	return m_sDatasetName.CopyTo(Name);
}

STDMETHODIMP CSimplePointDatasetHelper::get_ClassIndex(BSTR Name, long *Index)
{
	if (! Index) return E_POINTER;

	// This is a standalone feature class, so class index doesnt apply
  *Index = 0;

	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_Bounds(IEnvelope **Bounds)
{
	HRESULT hr;
	if (! Bounds) return E_POINTER;

  // Get an envelope for the extent of the dataset
  // We will have to calculate the extent by opening a cursor
  // on the dataset, and building up a minimum bounding rectangle 
  
  // Prepare to open a cursor.
  // Make the fieldmap, with values of -1 (attributes do not need fetching)

	long lNumFields;
	IFieldsPtr ipFields;
	
	hr = get_Fields(0, &ipFields);
	if (FAILED(hr)) return hr;

	hr = ipFields->get_FieldCount(&lNumFields);
	if (FAILED(hr)) return hr;

	CComVariant vFieldMap;
	vFieldMap.vt = VT_ARRAY | VT_I4;
  vFieldMap.parray = ::SafeArrayCreateVector(VT_I4, 0, lNumFields);
  long HUGEP *pMap = 0; // raw pointer to array
  hr = SafeArrayAccessData(vFieldMap.parray, (void HUGEP **)&pMap);
  if (FAILED(hr)) return hr;
	long i;
	for (i=0; i < lNumFields; i++)
		pMap[i] = -1;
	SafeArrayUnaccessData(vFieldMap.parray);  

	// Open the cursor
  IPlugInCursorHelperPtr ipPlugInCursor;
  hr = FetchAll(0, L"", vFieldMap, &ipPlugInCursor);
	if (FAILED(hr)) return hr;

	// loop through the data recording min/max X and Y values.
	double dxMin =  9999999;
  double dxMax = -9999999;
  double dyMin =  9999999;
  double dyMax = -9999999;
	double x,y;

	VARIANT_BOOL bEOF = VARIANT_FALSE;
	IGeometryPtr ipGeom;
	hr = ipGeom.CreateInstance(CLSID_Point);
	if (FAILED(hr)) return hr;

  IPointPtr ipPoint;

	long lNumRecords = 0;
  do
	{
		lNumRecords++;
		hr = ipPlugInCursor->QueryShape(ipGeom);
    if (FAILED(hr)) return hr;
    
		ipPoint = ipGeom;
		if (ipPoint == NULL) return E_FAIL;
    hr = ipPoint->QueryCoords(&x, &y);
		if (FAILED(hr)) return hr;

    if (x > dxMax) dxMax = x;
		if (x < dxMin) dxMin = x;
    if (y > dyMax) dyMax = y;
		if (y < dyMin) dyMin = y;

		hr = ipPlugInCursor->NextRecord();
		if (hr != S_OK)
		{
			hr = ipPlugInCursor->IsFinished(&bEOF);
      if (FAILED(hr)) return hr;
		}
	} while (!bEOF);

  // Handle special case of single point in file
  // - add a small amount, so that we will end up with an envelope rather than a point
  if (lNumRecords == 1)
	{
	  double dDelta = 0.01;
		if (dxMax != 0) 
			dDelta = dxMax / 1000;
    dxMax += dDelta;
		dyMax += dDelta;
	}

	// Create the envelope object, setting the appropriate spatial reference
  IEnvelopePtr ipEnv;
	hr = ipEnv.CreateInstance(CLSID_Envelope);
	if (FAILED(hr)) return hr;

	ISpatialReferencePtr ipSR;
	hr = ipSR.CreateInstance(CLSID_UnknownCoordinateSystem);
  if (FAILED(hr)) return hr;

	hr = ipEnv->putref_SpatialReference(ipSR);
	if (FAILED(hr)) return hr;

  hr = ipEnv->PutCoords(dxMin, dyMin, dxMax, dyMax);
	if (FAILED(hr)) return hr;

  *Bounds = ipEnv.Detach(); // pass ownership of object to client
	
	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_Fields(long ClassIndex, IFields **FieldSet)
{
	if (! FieldSet) return E_POINTER;
	
	HRESULT hr;
  
	// First get the standard fields for an feature class
	IObjectClassDescriptionPtr ipOCDesc;
	hr = ipOCDesc.CreateInstance(CLSID_FeatureClassDescription);
	if (FAILED(hr)) return hr;

	IFieldsPtr ipFields;
	hr = ipOCDesc->get_RequiredFields(&ipFields);
	if (FAILED(hr)) return hr;

  IFieldPtr ipField;

  // We will have: a shape field name of "shape"
  // an UnknownCoordinateSystem
  // Just need to change the geometry type to Point
	long i;
	long lNumFields;
	esriFieldType eFieldType;
	hr = ipFields->get_FieldCount(&lNumFields);
	if (FAILED(hr)) return hr;

	for (i=0; i < lNumFields; i++)
  {
    hr = ipFields->get_Field(i, &ipField);
		if (FAILED(hr)) return hr;

		hr = ipField->get_Type(&eFieldType);
		if (eFieldType == esriFieldTypeGeometry)
		{
			IGeometryDefPtr ipGeomDef;
			hr = ipField->get_GeometryDef(&ipGeomDef);
			if (FAILED(hr)) return hr;

  		IGeometryDefEditPtr ipGeomDefEdit = ipGeomDef;
			if (ipGeomDefEdit == NULL) return E_FAIL;

			hr = ipGeomDefEdit->put_GeometryType(esriGeometryPoint);
			if (FAILED(hr)) return hr;
		}
	}

		// Add the extra text field
	IFieldEditPtr ipFieldEdit;
	hr = ipFieldEdit.CreateInstance(CLSID_Field);
  if (FAILED(hr)) return hr;

	hr = ipFieldEdit->put_Name(L"Column1");
	if (FAILED(hr)) return hr;
	
	hr = ipFieldEdit->put_Type(esriFieldTypeString);
	if (FAILED(hr)) return hr;

	hr = ipFieldEdit->put_Length(1);
	if (FAILED(hr)) return hr;

  IFieldsEditPtr ipFieldsEdit = ipFields;
  if (ipFieldsEdit == NULL) return E_FAIL;

	ipField = ipFieldEdit;
	if (ipField == NULL) return E_FAIL;

  hr = ipFieldsEdit->AddField(ipField);
	if (FAILED(hr)) return hr;

  *FieldSet = ipFields.Detach(); // pass ownership of object to client 

	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_OIDFieldIndex(long ClassIndex, long *OIDFieldIndex)
{
	if (! OIDFieldIndex) return E_POINTER;

	*OIDFieldIndex = 0;

	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::get_ShapeFieldIndex(long ClassIndex, long *ShapeFieldIndex)
{
	if (! ShapeFieldIndex) return E_POINTER;
  
	*ShapeFieldIndex = 1;

	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::FetchByID(long ClassIndex, long ID, VARIANT FieldMap, IPlugInCursorHelper **cursorHelper)
{
	HRESULT hr;
	if (! cursorHelper) return E_POINTER;

	// Some parameters can be ignored since,
  //   ClassIndex is only relevant to feature datasets
  //   WhereClause is not appropriate since we are not supporting SQL
  ISimplePointCursorHelperPtr ipSimplePointCursorHelper;
  hr = ipSimplePointCursorHelper.CreateInstance(CLSID_SimplePointCursorHelper);
  if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->put_FieldMap(FieldMap);
	if (FAILED(hr)) return hr;

	IFieldsPtr ipFields;
	hr = get_Fields(0, &ipFields);
	if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->putref_Fields(ipFields);
	if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->put_OID(ID);
	if (FAILED(hr)) return hr;

	CComBSTR sFilePath;
	sFilePath = m_sWorkspacePath;
	sFilePath.Append(m_sDatasetName);
	sFilePath.Append(g_sExt);
  hr = ipSimplePointCursorHelper->put_FilePath(sFilePath);
	if (FAILED(hr)) return hr;

  IPlugInCursorHelperPtr ipPlugInCursorHelper;
	ipPlugInCursorHelper = ipSimplePointCursorHelper;
	if (ipPlugInCursorHelper == NULL) return E_FAIL;

  *cursorHelper = ipPlugInCursorHelper.Detach(); // Pass ownership of object back to client
	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::FetchAll(long ClassIndex, BSTR WhereClause, VARIANT FieldMap, IPlugInCursorHelper **cursorHelper)
{
	HRESULT hr;
	if (! cursorHelper) return E_POINTER;

	// Some parameters can be ignored since,
  //   ClassIndex is only relevant to feature datasets
  //   WhereClause is not appropriate since we are not supporting SQL
  ISimplePointCursorHelperPtr ipSimplePointCursorHelper;
  hr = ipSimplePointCursorHelper.CreateInstance(CLSID_SimplePointCursorHelper);
  if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->put_FieldMap(FieldMap);
	if (FAILED(hr)) return hr;

  IFieldsPtr ipFields;
	hr = get_Fields(0, &ipFields);
	if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->putref_Fields(ipFields);
	if (FAILED(hr)) return hr;

	CComBSTR sFilePath;
	sFilePath = m_sWorkspacePath;
	sFilePath.Append(m_sDatasetName);
	sFilePath.Append(g_sExt);
  hr = ipSimplePointCursorHelper->put_FilePath(sFilePath);
	if (FAILED(hr)) return hr;

  IPlugInCursorHelperPtr ipPlugInCursorHelper;
	ipPlugInCursorHelper = ipSimplePointCursorHelper;
	if (ipPlugInCursorHelper == NULL) return E_FAIL;

  *cursorHelper = ipPlugInCursorHelper.Detach(); // Pass ownership of object back to client
	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::FetchByEnvelope(long ClassIndex, IEnvelope *env, VARIANT_BOOL strictSearch, BSTR WhereClause, VARIANT FieldMap, IPlugInCursorHelper **cursorHelper)
{
	HRESULT hr;
	if (! cursorHelper) return E_POINTER;

	// Some parameters can be ignored since,
  //   ClassIndex is only relevant to feature datasets
  //   WhereClause is not appropriate since we are not supporting SQL
  ISimplePointCursorHelperPtr ipSimplePointCursorHelper;
  hr = ipSimplePointCursorHelper.CreateInstance(CLSID_SimplePointCursorHelper);
  if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->put_FieldMap(FieldMap);
	if (FAILED(hr)) return hr;

	IFieldsPtr ipFields;
	hr = get_Fields(0, &ipFields);
	if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->putref_Fields(ipFields);
	if (FAILED(hr)) return hr;

	hr = ipSimplePointCursorHelper->putref_QueryEnvelope(env);
	if (FAILED(hr)) return hr;

	CComBSTR sFilePath;
	sFilePath = m_sWorkspacePath;
	sFilePath.Append(m_sDatasetName);
	sFilePath.Append(g_sExt);
  hr = ipSimplePointCursorHelper->put_FilePath(sFilePath);
	if (FAILED(hr)) return hr;

  IPlugInCursorHelperPtr ipPlugInCursorHelper;
	ipPlugInCursorHelper = ipSimplePointCursorHelper;
	if (ipPlugInCursorHelper == NULL) return E_FAIL;

  *cursorHelper = ipPlugInCursorHelper.Detach(); // Pass ownership of object back to client
	return S_OK;
}


// ISimplePointDatasetHelper methods
STDMETHODIMP CSimplePointDatasetHelper::put_WorkspacePath(BSTR newVal)
{
	m_sWorkspacePath = newVal;
	return S_OK;
}

STDMETHODIMP CSimplePointDatasetHelper::put_DatasetName(BSTR newVal)
{
	m_sDatasetName = newVal;
	return S_OK;
}