[GIS] Getting from IFeatureClass on annotation feature class to IAnnoClass using ArcObjects

annotation;arcobjectsclassextensionscomtypespython

I am working in Python 2.6 and ArcGIS 10.0 through comtypes, so I have full ArcObjects access. For example, see the answer I tacked onto Accessing ArcObjects from Python?. That makes this strictly an object model traversal question.

I have an IFeatureClass on an annotation feature class. I need to get to IAnnoClass to get the ReferenceScale property.

How do I do that?

I am guessing that it starts with the Extension property inherited from IClass, but I may be way off base.

Best Answer

If a feature class is an annotation class, its IFeatureClass.Extension will be a reference to the AnnotationFeatureClassExtension coclass instance. It can be directly cast to IAnnoClass interface.

In short, you are right, the Extension property will be an object which implements IAnnoClass.

Related Solutions

ArcObjects Annotation – Getting Annotation Text Geometry as Polygon Using ArcObjects

For your first example, try IElement.QueryOutline:

QueryOutline returns a polygon representing the outline of the element. A valid polygon object must be passed in to the method along with the current display. The method then updates the polygon object. The results for point and line elements will be similar to the minimum bounding envelope returned by QueryBounds, while the results for polygon elements while be the actual outline of the element (not the bounding envelope).

As for your second example, it's much more difficult, but should be possible by first converting the annotation to a multi-part polygon and then getting the minimum area bounding rectangle of that polygon.

The following two links should have enough code to get you there, or very close, but they are in VBA, not C#:

How to convert annotation to polygon features (ArcGIS 10 VBA SDK Help)
- Here's a C# version of the above code someone made: Convert Annotation to Polygon Features sample fails on multi part annotation (IQueryGeometry.GetGeometry) (ESRI forums)
Re: Simplify irregular shape building to rectangle (ESRI forums)
- If this doesn't produce the desired rectangle you could also try using the Minimum Boundary Geometry geoprocessing tool with the RECTANGLE_BY_WIDTH option.

[GIS] Creating Annotation Feature Class using ArcObjects

Recently I wrote the method to copy annotation layer. Maybe you will find this code useful. From annotation layer you can get annotation feature class. You just need create instances of ISymbolCollection, IAnnotateLayerPropertiesCollection and IOverposterProperties.

    public static IAnnotationLayer CreateAnnotationLayer(IAnnotationLayer templateLayer, string name, IWorkspace workspace, IFeatureDataset featureDataset)
    {
        var templateFeatureClass = (templateLayer as IDisplayTable)?.DisplayTable as IFeatureClass;
        var annotationClassExtension = templateFeatureClass.Extension as IAnnotationClassExtension;

        //

        var symbolCollection = (annotationClassExtension.SymbolCollection as IClone)?.Clone() as ISymbolCollection;
        var annotationProperties = (annotationClassExtension.AnnoProperties as IClone)?.Clone() as IAnnotateLayerPropertiesCollection;
        var overposterProperties = (annotationClassExtension.OverposterProperties as IClone)?.Clone() as IOverposterProperties;

        //

        IGraphicsLayerScale graphicsLayerScale = new GraphicsLayerScaleClass();
        graphicsLayerScale.ReferenceScale = annotationClassExtension.ReferenceScale;
        graphicsLayerScale.Units = annotationClassExtension.ReferenceScaleUnits;

        //

        IObjectClassDescription ocDescription = new AnnotationFeatureClassDescriptionClass();
        IFeatureClassDescription fcDescription = (IFeatureClassDescription)ocDescription;

        IFields requiredFields = ocDescription.RequiredFields;
        int shapeFieldIndex = requiredFields.FindField(fcDescription.ShapeFieldName);
        IField shapeField = requiredFields.get_Field(shapeFieldIndex);
        IGeometryDef geometryDef = shapeField.GeometryDef;
        IGeometryDefEdit geometryDefEdit = (IGeometryDefEdit)geometryDef;
        geometryDefEdit.SpatialReference_2 = (templateFeatureClass as IGeoDataset).SpatialReference;

        //

        IAnnotationLayerFactory annotationLayerFactory = new FDOGraphicsLayerFactoryClass();
        return annotationLayerFactory.CreateAnnotationLayer(
            workspace as IFeatureWorkspace,
            featureDataset,
            name,
            geometryDef,
            null,
            annotationProperties,
            graphicsLayerScale,
            symbolCollection,
            false,
            false,
            false,
            true,
            overposterProperties,
            string.Empty);
    }

Best Answer

Related Solutions

ArcObjects Annotation – Getting Annotation Text Geometry as Polygon Using ArcObjects

[GIS] Creating Annotation Feature Class using ArcObjects

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