Engine中如何获取标注中unplacedlabels？

Public Sub ConvertLabels2Anno() 

''Interface Pointers necessary for accessing basic information about the map 

Dim pMxDoc As IMxDocument 

Dim pApp As IApplication 

Dim pMap As IMap 

Dim pAView As IActiveView 



''Interface Pointers necessary for getting information about the layer being labeled 

Dim pLayer As ILayer 

Dim pDataset As IDataset 

Dim pAnnotationLayer As IAnnotationLayer 

Dim pGeoFeatureLayer As IGeoFeatureLayer 

Dim pFClass As IFeatureClass 



''Interface Pointers necessary for setting up the labeling properties for conversion 

Dim pAnnotateLayerPropertiesCollection As IAnnotateLayerPropertiesCollection 

Dim pMapAnnoPropsColl As IAnnotateLayerPropertiesCollection 

Dim pAnnotateLayerProperties As IAnnotateLayerProperties 

Dim pLabelEngineLayerProperties As ILabelEngineLayerProperties2 

Dim pOverposterLayerProperties As IOverposterLayerProperties2 

Dim pClone As IClone 

Dim propsIndex As Long 



''Interface Pointers necessary for creating the Map Annotation Group 

Dim pCompositeGraphicsLayer As ICompositeGraphicsLayer 

Dim pRefScale As IGraphicsLayerScale 

Dim pGraphicsLayer As IGraphicsLayer 



''Interface Pointers necessary for performing labeling 

Dim pScreenDisplay As IScreenDisplay 

Dim pAnnotateMapProps As IAnnotateMapProperties 

Dim pAnnotateMap2 As IAnnotateMap2 

Dim pTrackCancel As ITrackCancel 

Dim pMapOverposter As IMapOverposter 

Dim pOverposterProperties As IOverposterProperties 

Dim pOverflowGraphicsContainer As IOverflowGraphicsContainer 

Dim pElement As IElement 

Dim pUnplacedElements As IElementCollection 

Dim lngUnplacedIndex As Long 

Dim lngUnplacedCount As Long 



''setup the document, map, and get the first layer 

Set pMxDoc = ThisDocument 

Set pMap = pMxDoc.FocusMap 

Set pLayer = pMap.Layer(0) 



''check to make sure map is valid 

If pMap Is Nothing Then 

MsgBox There is not an active map, vbCritical 

Exit Sub 

End If 



''see if the first layer is the proper type 

If TypeOf pLayer Is IGeoFeatureLayer Then 

Set pGeoFeatureLayer = pLayer 

Else 

''throw an error if the first layer is not a GeoFeatureLayer because only layers implementing this interface can be labeled 

MsgBox First layer in map must be feature layer, vbCritical 

End If 



Set pMapAnnoPropsColl = New AnnotateLayerPropertiesCollection ''a new properties collection which will be populated 



''loop through the properties collection of the layer 

''for each item, copy it to the new properties collection, 

''pull the symbol out for the SymbolCollection, and setup the ID 

Set pAnnotateLayerPropertiesCollection = pGeoFeatureLayer.AnnotationProperties 

For propsIndex = 0 To (pAnnotateLayerPropertiesCollection.Count - 1) 

pAnnotateLayerPropertiesCollection.QueryItem propsIndex, pAnnotateLayerProperties 

If Not pAnnotateLayerProperties Is Nothing Then 

''Clone the properties and add them to the new collection 

Set pClone = pAnnotateLayerProperties 

pMapAnnoPropsColl.Add pClone.Clone 

End If 

Next propsIndex 



''clear the pointer for later use in the sub 

Set pAnnotateLayerProperties = Nothing 



''get the overposter (label engine) properties from the map 

Set pMapOverposter = pMap 

Set pOverposterProperties = pMapOverposter.OverposterProperties 



''Get the maps basic graphics layer and add a new layer to it 

''We''ll put the labels into this new Annotation Group 

Set pCompositeGraphicsLayer = pMap.BasicGraphicsLayer 

Set pGraphicsLayer = pCompositeGraphicsLayer.AddLayer(ANNO_GROUP_NAME, pGeoFeatureLayer) 



''setup the scale on the annotation group 

Set pRefScale = pGraphicsLayer 

If pMap.ReferenceScale = 0 Then 

pRefScale.ReferenceScale = pMap.MapScale 

Else 

pRefScale.ReferenceScale = pMap.ReferenceScale 

End If 



''activate the graphics container for adding elements. 

Set pAView = pMap 

Set pScreenDisplay = pAView.ScreenDisplay 

pGraphicsLayer.Activate pScreenDisplay 



''Prepare the annotation properties for label placement 

For propsIndex = 0 To (pMapAnnoPropsColl.Count - 1) 

pMapAnnoPropsColl.QueryItem propsIndex, pAnnotateLayerProperties ''get the properties from the collection 

If Not pAnnotateLayerProperties Is Nothing Then 

Set pAnnotateLayerProperties.FeatureLayer = pGeoFeatureLayer ''point the properties to the feature layer 

Set pAnnotateLayerProperties.GraphicsContainer = pGraphicsLayer ''set the AnnoLayer as the destination for the labels 

pAnnotateLayerProperties.AddUnplacedToGraphicsContainer = False ''we do not want to add unplaced elements to the annotation group 

pAnnotateLayerProperties.CreateUnplacedElements = True ''ALWAYS create unplaced elements 

pAnnotateLayerProperties.DisplayAnnotation = True ''turn on the label class if it isn''t already 

pAnnotateLayerProperties.FeatureLinked = False ''This sample creates map annotation, so set this to false 

pAnnotateLayerProperties.LabelWhichFeatures = esriAllFeatures ''this creates labels/anno for the full extent. This can be changed to produce labels for the current extent, selection etc 

pAnnotateLayerProperties.UseOutput = True '' yes, we want to produce elements 

Set pLabelEngineLayerProperties = pAnnotateLayerProperties ''QI to LabelEngineLayerProperties 

Set pOverposterLayerProperties = pLabelEngineLayerProperties.OverposterLayerProperties ''Get the overposter layer properties from the LabelEngineLayerProps 

pOverposterLayerProperties.TagUnplaced = True ''add unplaced labels as unplaced (true) or placed (false) 

End If 

Next propsIndex 



''sort the collection so labels are placed in the proper order 

pMapAnnoPropsColl.Sort 



''populate AnnotateMapProperties with the prepared collection 

Set pAnnotateMapProps = New AnnotateMapProperties 

Set pAnnotateMapProps.AnnotateLayerPropertiesCollection = pMapAnnoPropsColl 





Set pTrackCancel = New CancelTracker ''cocreat a cancel tracker 



''get the current AnnotateMap object from the map 

''this ensures we are using the proper label engine 

Set pAnnotateMap2 = pMap.AnnotationEngine 



''Now, call Label which will populate the annotation group with labels based on the properties we setup 

''The Label method know to put the labels in the annotation group because we specify it as the destination 

''as the destination GraphicsContainer in the above preparation loop 

pAnnotateMap2.Label pOverposterProperties, pAnnotateMapProps, pMap, pTrackCancel 



''Handle unplaced elements and finish off the process 

For propsIndex = 0 To (pMapAnnoPropsColl.Count - 1) 

pMapAnnoPropsColl.QueryItem propsIndex, pAnnotateLayerProperties, Nothing, pUnplacedElements 

If Not pAnnotateLayerProperties Is Nothing Then 

''Get a reference to the graphics container and add the unplaced elements as unplaced 

lngUnplacedCount = lngUnplacedCount + pUnplacedElements.Count 

If pUnplacedElements.Count > 0 Then 

Set pOverflowGraphicsContainer = pGraphicsLayer 

For lngUnplacedIndex = 0 To (pUnplacedElements.Count - 1) 

pUnplacedElements.QueryItem lngUnplacedIndex, pElement 

''add the unplaced elements as unplaced using the IOverflowGraphicsContainer interface 

pOverflowGraphicsContainer.AddOverflowElement pElement 

Next lngUnplacedIndex 

End If 



''release the feature layer reference in the properties collection to be safe 

''in some cases, not doing this would lead to a circular reference 

Set pAnnotateLayerProperties.FeatureLayer = Nothing 

End If 

Next propsIndex 



''turn off labeling of feature layer 

pGeoFeatureLayer.DisplayAnnotation = False 



''refresh the map 

Set pAView = pMap 

''fire contents changed to fill the Overflow Annotation window 

pAView.ContentsChanged 

''Refresh the map 

pAView.Refresh 



''if we have unplaced labels, show the dialog 

Set pApp = Application ''get a refrence to the application to show the overflow dialog 

If lngUnplacedCount > 0 Then 

pApp.ShowDialog esriMxDlgOverflowLabels, True 

End If 



End Sub