问题
Is it possible to draw a symbol shadow behind the symbol fill? As explained here, CorePlot Issue 478 the fill is drawn after the plot fill which results in something that looks like this,
, where the red is the shadow and blue is the fill.
回答1:
Core Plot issue #478 is fixed. Pull the latest code to fix the symbol drawing.
If you don't want to do that, the fix involves adding a transparency layer to the symbol drawing. See the diff for the change to see how to fix your copy. The previous changeset fixes the -copyWithZone: issue mentioned on the issue tracker, too.
来源：https://stackoverflow.com/questions/13542456/how-to-draw-a-plot-symbol-shadow-behind-the-symbol-fill-in-coreplot