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C++ QgsVectorDataProvider::isValid方法代码示例

本文整理汇总了C++中QgsVectorDataProvider::isValid方法的典型用法代码示例。如果您正苦于以下问题:C++ QgsVectorDataProvider::isValid方法的具体用法?C++ QgsVectorDataProvider::isValid怎么用?C++ QgsVectorDataProvider::isValid使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在QgsVectorDataProvider的用法示例。


在下文中一共展示了QgsVectorDataProvider::isValid方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: mErrorCount

QgsVectorLayerImport::QgsVectorLayerImport( const QString &uri,
    const QString &providerKey,
    const QgsFields& fields,
    QGis::WkbType geometryType,
    const QgsCoordinateReferenceSystem* crs,
    bool overwrite,
    const QMap<QString, QVariant> *options,
    QProgressDialog *progress )
    : mErrorCount( 0 )
    , mAttributeCount( -1 )
    , mProgress( progress )

{
  mProvider = nullptr;

  QgsProviderRegistry * pReg = QgsProviderRegistry::instance();

  QLibrary *myLib = pReg->providerLibrary( providerKey );
  if ( !myLib )
  {
    mError = ErrInvalidProvider;
    mErrorMessage = QObject::tr( "Unable to load %1 provider" ).arg( providerKey );
    return;
  }

  createEmptyLayer_t * pCreateEmpty = reinterpret_cast< createEmptyLayer_t * >( cast_to_fptr( myLib->resolve( "createEmptyLayer" ) ) );
  if ( !pCreateEmpty )
  {
    delete myLib;
    mError = ErrProviderUnsupportedFeature;
    mErrorMessage = QObject::tr( "Provider %1 has no %2 method" ).arg( providerKey, "createEmptyLayer" );
    return;
  }

  delete myLib;

  // create an empty layer
  QString errMsg;
  mError = pCreateEmpty( uri, fields, geometryType, crs, overwrite, &mOldToNewAttrIdx, &errMsg, options );
  if ( hasError() )
  {
    mErrorMessage = errMsg;
    return;
  }

  Q_FOREACH ( int idx, mOldToNewAttrIdx.values() )
  {
    if ( idx > mAttributeCount )
      mAttributeCount = idx;
  }

  mAttributeCount++;

  QgsDebugMsg( "Created empty layer" );

  QgsVectorDataProvider *vectorProvider = dynamic_cast< QgsVectorDataProvider* >( pReg->provider( providerKey, uri ) );
  if ( !vectorProvider || !vectorProvider->isValid() || ( vectorProvider->capabilities() & QgsVectorDataProvider::AddFeatures ) == 0 )
  {
    mError = ErrInvalidLayer;
    mErrorMessage = QObject::tr( "Loading of layer failed" );

    if ( vectorProvider )
      delete vectorProvider;

    return;
  }

  mProvider = vectorProvider;
  mError = NoError;
}
开发者ID:BIbiLion,项目名称:QGIS,代码行数:70,代码来源:qgsvectorlayerimport.cpp

示例2: uriUpdated

QgsVectorLayerExporter::QgsVectorLayerExporter( const QString &uri,
    const QString &providerKey,
    const QgsFields &fields,
    QgsWkbTypes::Type geometryType,
    const QgsCoordinateReferenceSystem &crs,
    bool overwrite,
    const QMap<QString, QVariant> &options,
    QgsFeatureSink::SinkFlags sinkFlags )
  : mErrorCount( 0 )
  , mAttributeCount( -1 )

{
  mProvider = nullptr;

  QgsProviderRegistry *pReg = QgsProviderRegistry::instance();

  std::unique_ptr< QLibrary > myLib( pReg->createProviderLibrary( providerKey ) );
  if ( !myLib )
  {
    mError = ErrInvalidProvider;
    mErrorMessage = QObject::tr( "Unable to load %1 provider" ).arg( providerKey );
    return;
  }

  createEmptyLayer_t *pCreateEmpty = reinterpret_cast< createEmptyLayer_t * >( cast_to_fptr( myLib->resolve( "createEmptyLayer" ) ) );
  if ( !pCreateEmpty )
  {
    mError = ErrProviderUnsupportedFeature;
    mErrorMessage = QObject::tr( "Provider %1 has no %2 method" ).arg( providerKey, QStringLiteral( "createEmptyLayer" ) );
    return;
  }

  // create an empty layer
  QString errMsg;
  mError = pCreateEmpty( uri, fields, geometryType, crs, overwrite, &mOldToNewAttrIdx, &errMsg, !options.isEmpty() ? &options : nullptr );
  if ( errorCode() )
  {
    mErrorMessage = errMsg;
    return;
  }

  Q_FOREACH ( int idx, mOldToNewAttrIdx )
  {
    if ( idx > mAttributeCount )
      mAttributeCount = idx;
  }

  mAttributeCount++;

  QgsDebugMsg( QStringLiteral( "Created empty layer" ) );

  QString uriUpdated( uri );
  // HACK sorry...
  if ( providerKey == QLatin1String( "ogr" ) )
  {
    QString layerName;
    if ( options.contains( QStringLiteral( "layerName" ) ) )
      layerName = options.value( QStringLiteral( "layerName" ) ).toString();
    if ( !layerName.isEmpty() )
    {
      uriUpdated += QLatin1String( "|layername=" );
      uriUpdated += layerName;
    }
  }

  QgsDataProvider::ProviderOptions providerOptions;
  QgsVectorDataProvider *vectorProvider = dynamic_cast< QgsVectorDataProvider * >( pReg->createProvider( providerKey, uriUpdated, providerOptions ) );
  if ( !vectorProvider || !vectorProvider->isValid() || ( vectorProvider->capabilities() & QgsVectorDataProvider::AddFeatures ) == 0 )
  {
    mError = ErrInvalidLayer;
    mErrorMessage = QObject::tr( "Loading of layer failed" );

    delete vectorProvider;
    return;
  }

  // If the result is a geopackage layer and there is already a field name FID requested which
  // might contain duplicates, make sure to generate a new field with a unique name instead
  // that will be filled by ogr with unique values.

  // HACK sorry
  const QString path = QgsProviderRegistry::instance()->decodeUri( QStringLiteral( "ogr" ), uri ).value( QStringLiteral( "path" ) ).toString();
  if ( sinkFlags.testFlag( QgsFeatureSink::SinkFlag::RegeneratePrimaryKey ) && path.endsWith( QLatin1String( ".gpkg" ), Qt::CaseInsensitive ) )
  {
    QString fidName = options.value( QStringLiteral( "FID" ), QStringLiteral( "FID" ) ).toString();
    int fidIdx = vectorProvider->fields().lookupField( fidName );
    if ( fidIdx != -1 )
    {
      mOldToNewAttrIdx.remove( fidIdx );
    }
  }

  mProvider = vectorProvider;
  mError = NoError;
}
开发者ID:AlisterH,项目名称:Quantum-GIS,代码行数:95,代码来源:qgsvectorlayerexporter.cpp


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