topic Re: how to change symbol (fill, color etc) on selected features only in ArcObjects SDK Questions

how to change symbol (fill, color etc) on selected features only

RinatSolorzano_Palero — Thu, 12 Jul 2012 16:12:02 GMT

Hi everyone, i would like to know how to change the symbol properties on the selected features only, i want to fill it with linefillsymbol. Here's some code i've done but it doesnt work

Dim pFSel As IFeatureSelection
Set pFSel = pMap.Layer(0)

Dim pSelSet As ISelectionSet2
Dim pFeature As IFeature
Dim pFcursor As IFeatureCursor
Set pSelSet = pFSel.SelectionSet
pSelSet.Search Nothing, False, pFcursor
Set pFeature = pFcursor.NextFeature

Dim a As IFeatureRenderer
Dim pLSymbol As ILineFillSymbol
Set pLSymbol = New LineFillSymbol

Set a = pGFLayer.renderer
Set pLSymbol = a.SymbolByFeature(pFeature)

Dim pColor As IRgbColor
Set pColor = New RgbColor
pColor.RGB = RGB(255, 0, 0)
pLSymbol.color = pColor
pLSymbol.Separation = 7
pLSymbol.Angle = 70

'Dim padisplay As IDisplay
'Set padisplay = pMxDoc.ActiveView.ScreenDisplay
'padisplay.SetSymbol pLSymbol

'a.Draw pFcursor, esriDPSelection, padisplay, Nothing

pMxDoc.UpdateContents
pMxDoc.ActiveView.Refresh

thnks a lot!!

Re: how to change symbol (fill, color etc) on selected features only

PeterYurkosky1 — Thu, 12 Jul 2012 16:33:22 GMT

IFeatureRenderer.SymbolByFeature returns a copy of a symbol. So all this code is doing is copying a renderer's symbol and then changing the copy. Even if it were "by-reference", you'd be modifying the symbol for all features that use that symbol, whether they're selected or not. That's surely not what you want.

I'd suggest looping over the cursor you got from the selection set and drawing the symbol directly via ISymbol.Draw.

Re: how to change symbol (fill, color etc) on selected features only

RinatSolorzano_Palero — Thu, 12 Jul 2012 16:45:55 GMT

hi!, i've tried with the draw function from IFeatureRenderer using the cursor i have like this:

Dim pFSel As IFeatureSelection
Set pFSel = pMap.Layer(0)

Dim pSelSet As ISelectionSet2
Dim pFeature As IFeature
Dim pFcursor As IFeatureCursor
Set pSelSet = pFSel.SelectionSet
pSelSet.Search Nothing, False, pFcursor
Set pFeature = pFcursor.NextFeature

Dim a As IFeatureRenderer
Set a = pGFLayer.renderer
Dim pLSymbol As ILineFillSymbol
Set pLSymbol = New LineFillSymbol

Dim pColor As IRgbColor
Set pColor = New RgbColor
pColor.RGB = RGB(255, 0, 0)
pLSymbol.color = pColor
pLSymbol.Separation = 7
pLSymbol.Angle = 70

Dim padisplay As IDisplay
Set padisplay = pMxDoc.ActiveView.ScreenDisplay
padisplay.SetSymbol pLSymbol

a.Draw pFcursor, esriDPSelection, padisplay, Nothing

pMxDoc.UpdateContents
pMxDoc.ActiveView.Refresh

but i get an automation error, i'm not sure where's the mistake.... thanks for your help!!