C++ OGRFeatureDefn::GetFieldIndex方法代码示例

int OGRGFTResultLayer::RunSQL()
{
    CPLString osChangedSQL(osSQL);
    int bHasSetLimit = FALSE;
    OGRGFTTableLayer* poTableLayer = NULL;
    OGRFeatureDefn* poTableDefn = NULL;
    CPLString osTableId;
    if (EQUALN(osSQL.c_str(), "SELECT", 6))
    {
        size_t nPosFROM = osSQL.ifind(" FROM ");
        if (nPosFROM == std::string::npos)
        {
            CPLError(CE_Failure, CPLE_AppDefined, "RunSQL() failed. Missing FROM in SELECT");
            return FALSE;
        }
        CPLString osReminder;
        nPosFROM += 6;
        osTableId = OGRGFTExtractTableID(osSQL.c_str() + nPosFROM, osReminder);

        poTableLayer = (OGRGFTTableLayer*) poDS->GetLayerByName(osTableId);
        if (poTableLayer != NULL)
            poTableDefn = poTableLayer->GetLayerDefn();

        if (poTableLayer != NULL &&
            poTableLayer->GetTableId().size() &&
            !EQUAL(osTableId, poTableLayer->GetTableId()))
        {
            osChangedSQL = osSQL;
            osChangedSQL.resize(nPosFROM);
            osChangedSQL += poTableLayer->GetTableId();
            osChangedSQL += osReminder;
            osSQL = osChangedSQL;
            CPLDebug("GFT", "Patching table name (%s) to table id (%s)",
                     osTableId.c_str(), poTableLayer->GetTableId().c_str());
        }

        int nFeaturesToFetch = GetFeaturesToFetch();
        if (osSQL.ifind(" OFFSET ") == std::string::npos &&
            osSQL.ifind(" LIMIT ") == std::string::npos &&
            nFeaturesToFetch > 0)
        {
            osChangedSQL += CPLSPrintf(" LIMIT %d", nFeaturesToFetch);
            bHasSetLimit = TRUE;
        }
    }
    else
    {
        bGotAllRows = bEOF = TRUE;
        poFeatureDefn->SetGeomType( wkbNone );
    }

    CPLHTTPResult * psResult = poDS->RunSQL(osChangedSQL);

    if (psResult == NULL)
        return FALSE;

    char* pszLine = (char*) psResult->pabyData;
    if (pszLine == NULL ||
        psResult->pszErrBuf != NULL)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "RunSQL() failed");
        CPLHTTPDestroyResult(psResult);
        return FALSE;
    }

    if (EQUALN(osSQL.c_str(), "SELECT", 6) ||
        EQUAL(osSQL.c_str(), "SHOW TABLES") ||
        EQUALN(osSQL.c_str(), "DESCRIBE", 8))
    {
        ParseCSVResponse(pszLine, aosRows);
        if (aosRows.size() > 0)
        {
            char** papszTokens = OGRGFTCSVSplitLine(aosRows[0], ',');
            for(int i=0;papszTokens && papszTokens[i];i++)
            {
                CPLString osLaunderedColName(LaunderColName(papszTokens[i]));
                int iIndex = (poTableDefn) ? poTableDefn->GetFieldIndex(osLaunderedColName) : -1;
                if (iIndex >= 0)
                {
                    poFeatureDefn->AddFieldDefn(poTableDefn->GetFieldDefn(iIndex));
                    if (iIndex == poTableLayer->GetGeometryFieldIndex())
                        iGeometryField = i;
                    if (iIndex == poTableLayer->GetLatitudeFieldIndex())
                        iLatitudeField = i;
                    if (iIndex == poTableLayer->GetLongitudeFieldIndex())
                        iLongitudeField = i;
                }
                else
                {
                    OGRFieldType eType = OFTString;
                    if (EQUAL(osLaunderedColName, "COUNT()"))
                        eType = OFTInteger;
                    OGRFieldDefn oFieldDefn(osLaunderedColName, eType);
                    poFeatureDefn->AddFieldDefn(&oFieldDefn);
                }
            }
            CSLDestroy(papszTokens);

            aosRows.erase(aosRows.begin());
        }
//.........这里部分代码省略.........

/**********************************************************************
 *                          CreateIndex()
 *
 * Create index for specified field in an existing TAB dataset.
 **********************************************************************/
static int CreateIndex(const char *pszSrcFname, const char *pszField)
{
    IMapInfoFile *poSrcFile = NULL;
    int         nFeatureId, iField;
    TABFeature *poFeature;
    TABINDFile *poINDFile;

    /*---------------------------------------------------------------------
     * Try to open source file
     *--------------------------------------------------------------------*/
    if ((poSrcFile = IMapInfoFile::SmartOpen(pszSrcFname)) == NULL)
    {
        printf("Failed to open %s\n", pszSrcFname);
        return -1;
    }

    if (poSrcFile->GetFileClass() != TABFC_TABFile)
    {
        printf("Indexes cannot be added to this type of TAB datasets\n");
        poSrcFile->Close();
        delete poSrcFile;
        return -1;
    }

    /*---------------------------------------------------------------------
     * Make sure field exists and is not already indexed
     *--------------------------------------------------------------------*/
    OGRFeatureDefn *poDefn = poSrcFile->GetLayerDefn();
    if ( poDefn == NULL ||
         (iField = poDefn->GetFieldIndex(pszField)) == -1 ||
         poSrcFile->IsFieldIndexed(iField))
    {
        printf("Cannot create index: field '%s' not found or is already indexed.\n", 
               pszField);
        poSrcFile->Close();
        delete poSrcFile;
        return -1;
    }

    /*---------------------------------------------------------------------
     * Things seem OK... open IND file for update
     * (Note that TABINDFile automagically adjusts file extension)
     *--------------------------------------------------------------------*/
    poINDFile = new TABINDFile; 
    if ( poINDFile->Open(pszSrcFname, "r+", TRUE) != 0 &&
         poINDFile->Open(pszSrcFname, "w", TRUE) != 0)
    {
        printf("Unable to create IND file for %s.\n", pszSrcFname);
        delete poINDFile;
        poSrcFile->Close();
        delete poSrcFile;
        return -1;
    }

    int nNewIndexNo = -1;
    OGRFieldDefn *poFieldDefn = poDefn->GetFieldDefn(iField);
    TABFieldType eFieldType = poSrcFile->GetNativeFieldType(iField);
    if (poFieldDefn == NULL ||
        (nNewIndexNo = poINDFile->CreateIndex(eFieldType,
                                              poFieldDefn->GetWidth()) ) < 1)
    {
        // Failed... an error has already been reported.
        delete poINDFile;
        poSrcFile->Close();
        delete poSrcFile;
        return -1;
    }

    printf("Index number %d will be created for field %s...\n\n"
           "This program does not update the TAB header file (yet!) so you \n"
           "should edit %s and add 'Index %d' at the end of the definition \n"
           "of field %s.\n\n",
           nNewIndexNo, pszField, pszSrcFname, nNewIndexNo, pszField);

    /*---------------------------------------------------------------------
     * Add index entries until we reach EOF
     *--------------------------------------------------------------------*/
    nFeatureId = -1;
    while ( (nFeatureId = poSrcFile->GetNextFeatureId(nFeatureId)) != -1 )
    {
        poFeature = poSrcFile->GetFeatureRef(nFeatureId);
        if (poFeature)
        {
            GByte *pKey = NULL;
            switch(eFieldType)
            {
              case TABFChar:
                pKey = poINDFile->BuildKey(nNewIndexNo, 
                                        poFeature->GetFieldAsString(iField));
                break;
              case TABFInteger:
              case TABFSmallInt:
                pKey = poINDFile->BuildKey(nNewIndexNo, 
                                        poFeature->GetFieldAsInteger(iField));
                break;
//.........这里部分代码省略.........

bool OGRGeoJSONReader::GenerateFeatureDefn( json_object* poObj )
{
    OGRFeatureDefn* poDefn = poLayer_->GetLayerDefn();
    CPLAssert( NULL != poDefn );

    bool bSuccess = false;

/* -------------------------------------------------------------------- */
/*      Read collection of properties.									*/
/* -------------------------------------------------------------------- */
    json_object* poObjProps = NULL;
    poObjProps = OGRGeoJSONFindMemberByName( poObj, "properties" );
    if( NULL != poObjProps &&
        json_object_get_type(poObjProps) == json_type_object )
    {
        if (bIsGeocouchSpatiallistFormat)
        {
            poObjProps = json_object_object_get(poObjProps, "properties");
            if( NULL == poObjProps ||
                json_object_get_type(poObjProps) != json_type_object )
            {
                return true;
            }
        }

        json_object_iter it;
        it.key = NULL;
        it.val = NULL;
        it.entry = NULL;
        json_object_object_foreachC( poObjProps, it )
        {
            int nFldIndex = poDefn->GetFieldIndex( it.key );
            if( -1 == nFldIndex )
            {
                /* Detect the special kind of GeoJSON output by a spatiallist of GeoCouch */
                /* such as http://gd.iriscouch.com/cphosm/_design/geo/_rewrite/data?bbox=12.53%2C55.73%2C12.54%2C55.73 */
                if (strcmp(it.key, "_id") == 0)
                    bFoundId = true;
                else if (bFoundId && strcmp(it.key, "_rev") == 0)
                    bFoundRev = true;
                else if (bFoundRev && strcmp(it.key, "type") == 0 &&
                         it.val != NULL && json_object_get_type(it.val) == json_type_string &&
                         strcmp(json_object_get_string(it.val), "Feature") == 0)
                    bFoundTypeFeature = true;
                else if (bFoundTypeFeature && strcmp(it.key, "properties") == 0 &&
                         it.val != NULL && json_object_get_type(it.val) == json_type_object)
                {
                    if (bFlattenGeocouchSpatiallistFormat < 0)
                        bFlattenGeocouchSpatiallistFormat = CSLTestBoolean(
                            CPLGetConfigOption("GEOJSON_FLATTEN_GEOCOUCH", "TRUE"));
                    if (bFlattenGeocouchSpatiallistFormat)
                    {
                        poDefn->DeleteFieldDefn(poDefn->GetFieldIndex("type"));
                        bIsGeocouchSpatiallistFormat = true;
                        return GenerateFeatureDefn(poObj);
                    }
                }

                OGRFieldDefn fldDefn( it.key,
                    GeoJSONPropertyToFieldType( it.val ) );
                poDefn->AddFieldDefn( &fldDefn );
            }
            else
            {
                OGRFieldDefn* poFDefn = poDefn->GetFieldDefn(nFldIndex);
                OGRFieldType eType = poFDefn->GetType();
                if( eType == OFTInteger )
                {
                    OGRFieldType eNewType = GeoJSONPropertyToFieldType( it.val );
                    if( eNewType == OFTReal )
                        poFDefn->SetType(eNewType);
                }
            }
        }

        bSuccess = true; // SUCCESS
    }

//.........这里部分代码省略.........
        if (EQUALN(pszStr, "\"\\IsSeamless\" = \"TRUE\"", 21))
            bSeamlessFound = TRUE;
    }
    CSLDestroy(papszTABFile);

    if ( !bSeamlessFound )
    {
        if (!bTestOpenNoError)
            CPLError(CE_Failure, CPLE_NotSupported,
                     "%s does not appear to be a Seamless TAB File.  "
                     "This type of .TAB file cannot be read by this library.",
                     m_pszFname);
        else
            CPLErrorReset();

        CPLFree(m_pszFname);

        return -1;
    }

    /*-----------------------------------------------------------------
     * OK, this appears to be a valid seamless TAB dataset...
     * Extract the path component from the main .TAB filename
     * to build the filename of the base tables
     *----------------------------------------------------------------*/
    m_pszPath = CPLStrdup(m_pszFname);
    nFnameLen = strlen(m_pszPath);
    for( ; nFnameLen > 0; nFnameLen--)
    {
        if (m_pszPath[nFnameLen-1] == '/' || 
            m_pszPath[nFnameLen-1] == '\\' )
        {
            break;
        }
        m_pszPath[nFnameLen-1] = '\0';
    }

    /*-----------------------------------------------------------------
     * Open the main Index table and look for the "Table" field that
     * should contain the path to the base table for each rectangle MBR
     *----------------------------------------------------------------*/
    m_poIndexTable = new TABFile;
    if (m_poIndexTable->Open(m_pszFname, "rb", bTestOpenNoError) != 0)
    {
        // Open Failed... an error has already been reported, just return.
        if (bTestOpenNoError)
            CPLErrorReset();
        Close();
        return -1;
    }

    OGRFeatureDefn *poDefn = m_poIndexTable->GetLayerDefn();
    if (poDefn == NULL ||
        (m_nTableNameField = poDefn->GetFieldIndex("Table")) == -1)
    {
        if (!bTestOpenNoError)
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Open Failed: Field 'Table' not found in Seamless "
                     "Dataset '%s'.  This is type of file not currently "
                     "supported.",
                     m_pszFname);
        Close();
        return -1;        
    }

    /*-----------------------------------------------------------------
     * Check number of features in index table to make sure we won't
     * overflow the number of bytes used for table ids in the encoded
     * feature ids.  We currently use 12 bits for table id + 20 bits for FID
     *----------------------------------------------------------------*/
    if (m_poIndexTable->GetFeatureCount(FALSE) > 0x7ff)
    {
        if (!bTestOpenNoError)
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Open Failed: The current implementation is limited "
                     "to 2047 base tables.  The seamless file '%s' contains "
                     "%d tables and cannot be opened.",
                     m_pszFname, m_poIndexTable->GetFeatureCount(FALSE));
        Close();
        return -1;        
    }

    /*-----------------------------------------------------------------
     * We need to open the first table to get its FeatureDefn
     *----------------------------------------------------------------*/
    if (OpenBaseTable(-1, bTestOpenNoError) != 0 )
    {
        // Open Failed... an error has already been reported, just return.
        if (bTestOpenNoError)
            CPLErrorReset();
        Close();
        return -1;
    }

    CPLAssert(m_poCurBaseTable);
    m_poFeatureDefnRef = m_poCurBaseTable->GetLayerDefn();
    m_poFeatureDefnRef->Reference();

    return 0;
}

OGRFeatureDefn *
OGROCISelectLayer::ReadTableDefinition( OGROCIStatement *poCommand )

{
    OGROCISession      *poSession = poDS->GetSession();

/* -------------------------------------------------------------------- */
/*      Parse the returned table information.                           */
/* -------------------------------------------------------------------- */
    for( int iParm = 0; TRUE; iParm++ )
    {                                                           
        OGRFieldDefn oField( "", OFTString );
        int          nStatus;
        OCIParam     *hParmDesc;
        ub2          nOCIType;
        ub4          nOCILen;

        nStatus = 
            OCIParamGet( poCommand->GetStatement(), OCI_HTYPE_STMT, 
                         poSession->hError, (dvoid**)&hParmDesc, 
                         (ub4) iParm+1 );

        if( nStatus == OCI_ERROR )
            break;

        if( poSession->GetParmInfo( hParmDesc, &oField, &nOCIType, &nOCILen )
            != CE_None )
            break;

        if( oField.GetType() == OFTBinary && nOCIType == 108 )
        {
            CPLFree( pszGeomName );
            pszGeomName = CPLStrdup( oField.GetNameRef() );
            iGeomColumn = iParm;
            break;
        }
    }

/* -------------------------------------------------------------------- */
/*      Use the schema off the statement.                               */
/* -------------------------------------------------------------------- */
    OGRFeatureDefn *poDefn;

    poDefn = poCommand->GetResultDefn();
    if( iGeomColumn >= 0 )
        poDefn->SetGeomType(wkbUnknown);
    poDefn->Reference();

/* -------------------------------------------------------------------- */
/*      Do we have an FID?                                              */
/* -------------------------------------------------------------------- */
    const char *pszExpectedFIDName = 
        CPLGetConfigOption( "OCI_FID", "OGR_FID" );
    if( poDefn->GetFieldIndex(pszExpectedFIDName) > -1 )
    {
        iFIDColumn = poDefn->GetFieldIndex(pszExpectedFIDName);
        pszFIDName = CPLStrdup(poDefn->GetFieldDefn(iFIDColumn)->GetNameRef());
    }

    if( EQUAL(pszExpectedFIDName, "OGR_FID") && pszFIDName )
    {
        for(int i=0;i<poDefn->GetFieldCount();i++)
        {
            // This is presumably a Integer since we always create Integer64 with a
            // defined precision
            if( poDefn->GetFieldDefn(i)->GetType() == OFTInteger64 &&
                poDefn->GetFieldDefn(i)->GetWidth() == 0 )
            {
                poDefn->GetFieldDefn(i)->SetType(OFTInteger);
            }
        }
    }

    return poDefn;
}

void readQuadIndex(int series, QString file, QString layerName, Projection *pj)
{
  OGRDataSource       *ds = OGRSFDriverRegistrar::Open(file.toLatin1().data(), false);
  if (!ds) {
    fprintf(stderr, "Could not open quad index '%s'.\n", file.toLatin1().data());
    exit(-1);
  }

  OGRLayer  *layer;
  layer = ds->GetLayerByName(layerName.toLatin1().data());
  if (!layer) {
    fprintf(stderr, "Could not read layer '%s'.\n", layerName.toLatin1().data());
    exit(-1);
  }

  OGRSpatialReference *srs = layer->GetSpatialRef();
  if (!srs) {
    fprintf(stderr, "Missing spatial reference for layer '%s'.\n", 
            layerName.toLatin1().data());
    exit(-1);
  }
  char *proj = NULL;
  srs->exportToProj4(&proj);
  if (!proj) {
    fprintf(stderr, "Error computing PROJ4 spatial reference for layer '%s'.\n", 
            layerName.toLatin1().data());
    exit(-1);
  }
  Projection pjIndex(proj);
  CPLFree(proj);


  layer->ResetReading();
  OGRFeatureDefn *def = layer->GetLayerDefn();

  int idFieldNr = def->GetFieldIndex("ID");
  int nameFieldNr = def->GetFieldIndex("NAME");
  if (idFieldNr < 0 || nameFieldNr < 0) {
    fprintf(stderr, "Missing index layer fields.\n");
    exit(-1);
  }


  OGRFeature *f;
  while ((f = layer->GetNextFeature()) != NULL) {
    QString id(f->GetFieldAsString(idFieldNr));
    QString name(f->GetFieldAsString(nameFieldNr));

    //    printf("Quad id: %s; name: %s\n", id.toLatin1().data(), name.toLatin1().data());

    OGRGeometry *g;
    g = f->GetGeometryRef();
    if (g != NULL && wkbFlatten(g->getGeometryType()) == wkbPolygon) {
      OGRPolygon *p = (OGRPolygon *)g;
      OGRLinearRing *r = p->getExteriorRing();
      if (!r) {
        fprintf(stderr, "Quad has no exterior polygon ring %s\n", 
                id.toLatin1().data());
        continue;
      }

      int size = r->getNumPoints();
      QPolygonF boundary;
      for (int i = 0; i < size; i++) {
        OGRPoint p;
        r->getPoint(i, &p);
        boundary << QPointF(p.getX(), p.getY());
      }

      QPolygonF projBoundary = pj->transformFrom(&pjIndex, boundary);
      
      quads[id] = Quad(series, id, name, projBoundary);
    } else {
      fprintf(stderr, "Missing or invalid geometry for quad %s\n", 
              id.toLatin1().data());
    }
  }

  OGRDataSource::DestroyDataSource(ds);
}

void OgrWriter::_createLayer(shared_ptr<const Layer> layer)
{
  OGRLayer *poLayer;

  OGRwkbGeometryType gtype;
  switch(layer->getGeometryType())
  {
  case GEOS_POINT:
    gtype = wkbPoint;
    break;
  case GEOS_LINESTRING:
    gtype = wkbLineString;
    break;
  case GEOS_POLYGON:
    gtype = wkbPolygon;
    break;
  default:
    throw HootException("Unexpected geometry type.");
  }

  OgrOptions options;
  if (_ds->GetDriver())
  {
    // if this is a CSV file
    if (_ds->GetDriver()->GetName() == QString("CSV"))
    {
      // if we're exporting point data, then export with x/y at the front
      if (gtype == wkbPoint)
      {
        options["GEOMETRY"] = "AS_XY";
      }
      // if we're exporting other geometries then export w/ WKT at the front.
      else
      {
        options["GEOMETRY"] = "AS_WKT";
      }
      options["CREATE_CSVT"] = "YES";
    }

    if (_ds->GetDriver()->GetName() == QString("ESRI Shapefile"))
    {
      options["ENCODING"] = "UTF-8";
    }

    // Add a Feature Dataset to a ESRI File GeoDatabase if requested
    if (_ds->GetDriver()->GetName() == QString("FileGDB"))
    {
      if (layer->getFdName() != "")
      {
        options["FEATURE_DATASET"] = layer->getFdName();
        // speed up bulk inserts.
        options["FGDB_BULK_LOAD"] = "YES";
      }
    }
  }

  QString layerName = _prependLayerName + layer->getName();

  // Check if the layer exists in the output.
  poLayer = _ds->GetLayerByName(layerName.toAscii());

  // We only want to add to a layer IFF the config option "ogr.append.data" set
  if (poLayer != NULL && _appendData)
  {
    // Layer exists
    _layers[layer->getName()] = poLayer;
    // Loop through the fields making sure that they exist in the output. Print a warning if
    // they don't exist
    OGRFeatureDefn *poFDefn = poLayer->GetLayerDefn();

    shared_ptr<const FeatureDefinition> fd = layer->getFeatureDefinition();
    for (size_t i = 0; i < fd->getFieldCount(); i++)
    {
      shared_ptr<const FieldDefinition> f = fd->getFieldDefinition(i);

      if (poFDefn->GetFieldIndex(f->getName().toAscii()) == -1)
      {
        //        throw HootException(QString("Error: Unable to find output field: %1 in layer %2.").arg(f->getName()).arg(layerName));
        LOG_WARN("Unable to find field: " << QString(f->getName()) << " in layer " << layerName);
      }
    }
  }
  else
  {
    // Layer does not exist
    poLayer = _ds->CreateLayer(layerName.toAscii(),
                  MapReprojector::createWgs84Projection()->Clone(), gtype, options.getCrypticOptions());

    if( poLayer == NULL )
    {
      throw HootException(QString("Layer creation failed. %1").arg(layerName));
    }
    _layers[layer->getName()] = poLayer;

    shared_ptr<const FeatureDefinition> fd = layer->getFeatureDefinition();
    for (size_t i = 0; i < fd->getFieldCount(); i++)
    {
      shared_ptr<const FieldDefinition> f = fd->getFieldDefinition(i);
      OGRFieldDefn oField(f->getName().toAscii(), toOgrFieldType(f->getType()));
      if (f->getWidth() > 0)
//.........这里部分代码省略.........

void OGRUnionLayer::ConfigureActiveLayer()
{
    AutoWarpLayerIfNecessary(iCurLayer);
    ApplyAttributeFilterToSrcLayer(iCurLayer);
    SetSpatialFilterToSourceLayer(papoSrcLayers[iCurLayer]);
    papoSrcLayers[iCurLayer]->ResetReading();

    /* Establish map */
    OGRFeatureDefn* poFeatureDefn = GetLayerDefn();
    OGRFeatureDefn* poSrcFeatureDefn = papoSrcLayers[iCurLayer]->GetLayerDefn();
    CPLFree(panMap);
    panMap = (int*) CPLMalloc(poSrcFeatureDefn->GetFieldCount() * sizeof(int));
    for(int i=0; i < poSrcFeatureDefn->GetFieldCount(); i++)
    {
        OGRFieldDefn* poSrcFieldDefn = poSrcFeatureDefn->GetFieldDefn(i);
        if( CSLFindString(papszIgnoredFields,
                          poSrcFieldDefn->GetNameRef() ) == -1 )
        {
            panMap[i] =
                poFeatureDefn->GetFieldIndex(poSrcFieldDefn->GetNameRef());
        }
        else
        {
            panMap[i] = -1;
        }
    }

    if( papoSrcLayers[iCurLayer]->TestCapability(OLCIgnoreFields) )
    {
        char** papszIter = papszIgnoredFields;
        char** papszFieldsSrc = NULL;
        while ( papszIter != NULL && *papszIter != NULL )
        {
            const char* pszFieldName = *papszIter;
            if ( EQUAL(pszFieldName, "OGR_GEOMETRY") ||
                    EQUAL(pszFieldName, "OGR_STYLE") ||
                    poSrcFeatureDefn->GetFieldIndex(pszFieldName) >= 0 ||
                    poSrcFeatureDefn->GetGeomFieldIndex(pszFieldName) >= 0 )
            {
                papszFieldsSrc = CSLAddString(papszFieldsSrc, pszFieldName);
            }
            papszIter++;
        }

        /* Attribute fields */
        int* panSrcFieldsUsed = (int*) CPLCalloc(sizeof(int),
                                poSrcFeatureDefn->GetFieldCount());
        for(int iField = 0;
                iField < poFeatureDefn->GetFieldCount(); iField++)
        {
            OGRFieldDefn* poFieldDefn = poFeatureDefn->GetFieldDefn(iField);
            int iSrcField =
                poSrcFeatureDefn->GetFieldIndex(poFieldDefn->GetNameRef());
            if (iSrcField >= 0)
                panSrcFieldsUsed[iSrcField] = TRUE;
        }
        for(int iSrcField = 0;
                iSrcField < poSrcFeatureDefn->GetFieldCount(); iSrcField ++)
        {
            if( !panSrcFieldsUsed[iSrcField] )
            {
                OGRFieldDefn *poSrcDefn =
                    poSrcFeatureDefn->GetFieldDefn( iSrcField );
                papszFieldsSrc =
                    CSLAddString(papszFieldsSrc, poSrcDefn->GetNameRef());
            }
        }
        CPLFree(panSrcFieldsUsed);

        /* geometry fields now */
        panSrcFieldsUsed = (int*) CPLCalloc(sizeof(int),
                                            poSrcFeatureDefn->GetGeomFieldCount());
        for(int iField = 0;
                iField < poFeatureDefn->GetGeomFieldCount(); iField++)
        {
            OGRGeomFieldDefn* poFieldDefn = poFeatureDefn->GetGeomFieldDefn(iField);
            int iSrcField =
                poSrcFeatureDefn->GetGeomFieldIndex(poFieldDefn->GetNameRef());
            if (iSrcField >= 0)
                panSrcFieldsUsed[iSrcField] = TRUE;
        }
        for(int iSrcField = 0;
                iSrcField < poSrcFeatureDefn->GetGeomFieldCount(); iSrcField ++)
        {
            if( !panSrcFieldsUsed[iSrcField] )
            {
                OGRGeomFieldDefn *poSrcDefn =
                    poSrcFeatureDefn->GetGeomFieldDefn( iSrcField );
                papszFieldsSrc =
                    CSLAddString(papszFieldsSrc, poSrcDefn->GetNameRef());
            }
        }
        CPLFree(panSrcFieldsUsed);

        papoSrcLayers[iCurLayer]->SetIgnoredFields((const char**)papszFieldsSrc);

        CSLDestroy(papszFieldsSrc);
    }
}

OGRFeatureDefn *OGRUnionLayer::GetLayerDefn()
{
    if( poFeatureDefn != NULL )
        return poFeatureDefn;

    poFeatureDefn = new OGRFeatureDefn( osName );
    poFeatureDefn->Reference();
    poFeatureDefn->SetGeomType(wkbNone);

    int iCompareFirstIndex = 0;
    if( osSourceLayerFieldName.size() )
    {
        OGRFieldDefn oField(osSourceLayerFieldName, OFTString);
        poFeatureDefn->AddFieldDefn(&oField);
        iCompareFirstIndex = 1;
    }

    if( eFieldStrategy == FIELD_SPECIFIED )
    {
        int i;
        for(i = 0; i < nFields; i++)
            poFeatureDefn->AddFieldDefn(papoFields[i]);
        for(i = 0; i < nGeomFields; i++)
        {
            poFeatureDefn->AddGeomFieldDefn(new OGRUnionLayerGeomFieldDefn(papoGeomFields[i]), FALSE);
            OGRUnionLayerGeomFieldDefn* poGeomFieldDefn =
                (OGRUnionLayerGeomFieldDefn* ) poFeatureDefn->GetGeomFieldDefn(i);

            if( poGeomFieldDefn->bGeomTypeSet == FALSE ||
                    poGeomFieldDefn->bSRSSet == FALSE )
            {
                for(int iLayer = 0; iLayer < nSrcLayers; iLayer++)
                {
                    OGRFeatureDefn* poSrcFeatureDefn =
                        papoSrcLayers[iLayer]->GetLayerDefn();
                    int nIndex =
                        poSrcFeatureDefn->GetGeomFieldIndex(poGeomFieldDefn->GetNameRef());
                    if( nIndex >= 0 )
                    {
                        OGRGeomFieldDefn* poSrcGeomFieldDefn =
                            poSrcFeatureDefn->GetGeomFieldDefn(nIndex);
                        if( poGeomFieldDefn->bGeomTypeSet == FALSE )
                        {
                            poGeomFieldDefn->bGeomTypeSet = TRUE;
                            poGeomFieldDefn->SetType(poSrcGeomFieldDefn->GetType());
                        }
                        if( poGeomFieldDefn->bSRSSet == FALSE )
                        {
                            poGeomFieldDefn->bSRSSet = TRUE;
                            poGeomFieldDefn->SetSpatialRef(poSrcGeomFieldDefn->GetSpatialRef());
                            if( i == 0 && poGlobalSRS == NULL )
                            {
                                poGlobalSRS = poSrcGeomFieldDefn->GetSpatialRef();
                                if( poGlobalSRS != NULL )
                                    poGlobalSRS->Reference();
                            }
                        }
                        break;
                    }
                }
            }
        }
    }
    else if( eFieldStrategy == FIELD_FROM_FIRST_LAYER )
    {
        OGRFeatureDefn* poSrcFeatureDefn = papoSrcLayers[0]->GetLayerDefn();
        int i;
        for(i = 0; i < poSrcFeatureDefn->GetFieldCount(); i++)
            poFeatureDefn->AddFieldDefn(poSrcFeatureDefn->GetFieldDefn(i));
        for(i = 0;  nGeomFields != - 1 && i < poSrcFeatureDefn->GetGeomFieldCount(); i++)
        {
            OGRGeomFieldDefn* poFldDefn = poSrcFeatureDefn->GetGeomFieldDefn(i);
            poFeatureDefn->AddGeomFieldDefn(
                new OGRUnionLayerGeomFieldDefn(poFldDefn), FALSE);
        }
    }
    else if (eFieldStrategy == FIELD_UNION_ALL_LAYERS )
    {
        if( nGeomFields == 1 )
        {
            poFeatureDefn->AddGeomFieldDefn(
                new OGRUnionLayerGeomFieldDefn(papoGeomFields[0]), FALSE);
        }

        for(int iLayer = 0; iLayer < nSrcLayers; iLayer++)
        {
            OGRFeatureDefn* poSrcFeatureDefn =
                papoSrcLayers[iLayer]->GetLayerDefn();

            /* Add any field that is found in the source layers */
            int i;
            for(i = 0; i < poSrcFeatureDefn->GetFieldCount(); i++)
            {
                OGRFieldDefn* poSrcFieldDefn = poSrcFeatureDefn->GetFieldDefn(i);
                int nIndex =
                    poFeatureDefn->GetFieldIndex(poSrcFieldDefn->GetNameRef());
                if( nIndex < 0 )
                    poFeatureDefn->AddFieldDefn(poSrcFieldDefn);
                else
                {
//.........这里部分代码省略.........

OGRFeatureDefn *OGRUnionLayer::GetLayerDefn()
{
    if( poFeatureDefn != NULL )
        return poFeatureDefn;

    poFeatureDefn = new OGRFeatureDefn( osName );
    poFeatureDefn->Reference();

    int iCompareFirstIndex = 0;
    if( osSourceLayerFieldName.size() )
    {
        OGRFieldDefn oField(osSourceLayerFieldName, OFTString);
        poFeatureDefn->AddFieldDefn(&oField);
        iCompareFirstIndex = 1;
    }

    if( eFieldStrategy == FIELD_SPECIFIED )
    {
        for(int i = 0; i < nFields; i++)
            poFeatureDefn->AddFieldDefn(papoFields[i]);
    }
    else if( eFieldStrategy == FIELD_FROM_FIRST_LAYER )
    {
        OGRFeatureDefn* poSrcFeatureDefn = papoSrcLayers[0]->GetLayerDefn();
        for(int i = 0; i < poSrcFeatureDefn->GetFieldCount(); i++)
            poFeatureDefn->AddFieldDefn(poSrcFeatureDefn->GetFieldDefn(i));
    }
    else if (eFieldStrategy == FIELD_UNION_ALL_LAYERS )
    {
        for(int iLayer = 0; iLayer < nSrcLayers; iLayer++)
        {
            OGRFeatureDefn* poSrcFeatureDefn =
                                papoSrcLayers[iLayer]->GetLayerDefn();

            /* Add any field that is found in the source layers */
            for(int i = 0; i < poSrcFeatureDefn->GetFieldCount(); i++)
            {
                OGRFieldDefn* poSrcFieldDefn = poSrcFeatureDefn->GetFieldDefn(i);
                int nIndex =
                    poFeatureDefn->GetFieldIndex(poSrcFieldDefn->GetNameRef());
                if( nIndex < 0 )
                    poFeatureDefn->AddFieldDefn(poSrcFieldDefn);
                else
                {
                    OGRFieldDefn* poFieldDefn =
                                        poFeatureDefn->GetFieldDefn(nIndex);
                    MergeFieldDefn(poFieldDefn, poSrcFieldDefn);
                }
            }
        }
    }
    else if (eFieldStrategy == FIELD_INTERSECTION_ALL_LAYERS )
    {
        OGRFeatureDefn* poSrcFeatureDefn = papoSrcLayers[0]->GetLayerDefn();
        int i;
        for(i = 0; i < poSrcFeatureDefn->GetFieldCount(); i++)
            poFeatureDefn->AddFieldDefn(poSrcFeatureDefn->GetFieldDefn(i));

        /* Remove any field that is not found in the source layers */
        for(int iLayer = 1; iLayer < nSrcLayers; iLayer++)
        {
            OGRFeatureDefn* poSrcFeatureDefn =
                                        papoSrcLayers[iLayer]->GetLayerDefn();
            for(i = iCompareFirstIndex; i < poFeatureDefn->GetFieldCount();)
            {
                OGRFieldDefn* poFieldDefn = poFeatureDefn->GetFieldDefn(i);
                int nSrcIndex = poSrcFeatureDefn->GetFieldIndex(
                                                    poFieldDefn->GetNameRef());
                if( nSrcIndex < 0 )
                {
                    poFeatureDefn->DeleteFieldDefn(i);
                }
                else
                {
                    OGRFieldDefn* poSrcFieldDefn =
                        poSrcFeatureDefn->GetFieldDefn(nSrcIndex);
                    MergeFieldDefn(poFieldDefn, poSrcFieldDefn);

                    i ++;
                }
            }
        }
    }

    poFeatureDefn->SetGeomType(GetGeomType());

    return poFeatureDefn;
}