about custom symbol

Discussion created by ts_chen on Nov 5, 2012
I write an ATL like logomarkersymbol. It inherits from ISymbol, ILineSymbol?????? It has three import function:
CCartoSymbolPolygon::SetupDC(OLE_HANDLE hDC, ITransformation *Transformation)
CCartoSymbolPolygon::Draw(IGeometry *Geometry)

I use an third graphic libary and I have a function Render2Hdc that paste the image memory to hdc. when I put this function into Draw. The symbol render correctly but very slowly. So, I want to draw all the features into memory. and finally I invoke the Render2Hdc. I put Render2Hdc into ResetDC. but now in the map, the symbl can't render. (in symbol preview window, it is correct) Why?? How to solve this problem to ensure that the rendering process is very fast.