Discover renderer line symbol type

[MartinLewis]

I'm trying to figure out how to discover if the symbol class from a simple renderer is CartographicLineSymbol in vb.NET

According to the documentation ISimpleRenderer.Symbol returns ISymbol.

According to the documentation ISymbol implements several line symbol classes (CartographicLineSymbol, HashLineSymbol, etc.)

I set layer's symbol "Type" to "Cartographic Line Symbol" in the properties and yet this code is not working:

                Dim rendLinks As ISimpleRenderer = geoLyrLinks.Renderer
                Dim aSymbol As ISymbol = rendLinks.Symbol
                If TypeOf aSymbol Is ICartographicLineSymbol Then
                    MessageBox.Show("i'm a cartographiclinesymbol")
                Else
                    MessageBox.Show("NOT a cartographiclinesymbol")
                End If

Can someone tell me what I'm doing wrong?  Or can someone tell me how to simply retrieve the symbol class from a simple renderer?

[MartinLewis]

In the code above:

Dim aSymbol as ISymbol = rendLinks.Symbol

seems to return aSymbol as type ILineSymbol, regardless of what symbol class is defined in the renderer.

[NeilClemmons · Accepted solution]

It's probably a IMultiLayerLineSymbol if you set it through the UI.  If it is, you'll need to loop through the layers in the symbol to find the one you're looking for.

[MartinLewis]

Thank you so much.  I just happened to stumble on a similar thread that was pointing me in this direction, but your tip got me there faster.

I just tested this - it seems that when changing the line symbol through ArcMap (Symbol Selector>Edit Symbol>Symbol Property Editor) and selecting Cartographic Line Symbol the new symbol is a IMultiLayerLineSymbol.

Now I just need to figure out how to loop thru the layers.