How to code a Shart/Graph Control in iOS?

I'm looking for a tutorial that shows me how I can create a custom Control for iOS, that draws Graphs. For example, something like in the Stocks App in iOS. Yes, there are many Chart Libraries out there but I find them really complex to learn the code and I just want to learn how I create such a graph myself in Code and how to create a Control from my Code that appears in the Interface Builder Library since I hav开发者_高级运维e never ever created a control myself. Does anyone got a hint?

Thank you very much

In the basic case, this is just a matter of drawing simple paths (in the Stocks app's case, they fill the path as well). Take a look at the Quartz 2D Programming Guide. It allows for all kinds of path-based drawing. On iPad and iOS 4, there's also UIBezierPath.