Saturday, September 11, 2010

Balloon Callout i ArcGIS Engine.

Anpassat ett exempel i VBA dokumentationen "How to add balloon callout" så att den fungerar i ArcGIS Engine. Inga stora förändringar krävdes utan det räckte med att byta ut så att ActiveView inte hämtas via MxDocument utan MapControl. Bryter man dessutom ut ActiveView till att vara en inparameter så fungerar dessutom exemplet i både desktop och engine.

 Private Sub AddBalloonCallout(ByVal activeView As IActiveView)  
Dim pTextElement As ITextElement
Dim pElement As IElement
Dim pPoint As IPoint
Dim pCallout As ICallout
Dim pTextSymbol As IFormattedTextSymbol
Dim pGraphicsContainer As IGraphicsContainer
Dim midX As Double, midY As Double
'Create a new text element
pTextElement = New TextElement
pElement = CType(pTextElement, IElement) 'QI
pTextElement.Text = "Text callout" & vbCrLf & "In the middle of the screen"
'Position the new element on the active view's center point
midX = (activeView.Extent.XMax + activeView.Extent.XMin) / 2
midY = (activeView.Extent.YMax + activeView.Extent.YMin) / 2
pPoint = New Point
pPoint.PutCoords(midX, midY)
pElement.Geometry = pPoint
'Set the text element symbology to a default balloon callout
pTextSymbol = New TextSymbol
pCallout = New BalloonCallout
pTextSymbol.Background = CType(pCallout, ITextBackground)
'Use this formula to get a callout anchor point location
pPoint.PutCoords(midX - activeView.Extent.Width / 4, midY + activeView.Extent.Width / 20)
pCallout.AnchorPoint = pPoint
pTextElement.Symbol = pTextSymbol
'Add the element to the active view, either the focus Map or PageLayout
pGraphicsContainer = CType(activeView, IGraphicsContainer)
pGraphicsContainer.AddElement(pElement, 0)
pElement.Activate(activeView.ScreenDisplay)
'Flag the area of the new element for refreshing
activeView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, pElement, Nothing)
End Sub

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