UIGraphicsBeginImageContextWithOptions undeclared

Greetings!

I'm attempting to build an iPhone application that makes use of an iOS4-only function: 'UIGraphicsBeginImageConte开发者_开发百科xtWithOptions'.

I'm building for iPhone device 3.1.3 in XCode 3.2.1 and getting errors about that function not being defined.

This stackoverflow page already showed me that I should link weakly against UIKit and check that function for NULL, I am already doing this:

However, build still fails with:

Anyone have any idea?

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You need to build against the iOS 4.x SDK, otherwise the compiler has no knowledge of that function.