xcode error: there is no sdk for "iphoneos2.2.1"

So I downloaded a sample application and I'm guessing it was made before the iphone os 4. And when I try to compile it gives me that error.

I don't know if the programming would be any different. Can someone tell me if there were any c开发者_JAVA技巧hanges in programming between os 2.2.1 and os 4? How do I make this application compatible for os 4?

Thanks, Elijah

Yes, there have been changes. You should read the docs on developer.apple.com to get up to speed.

If you are on the latest version of the SDK but have a project that is targeting an older version that you don't have you can change the target by highlighting the project file in xcode and clicking the info button, then change the 'Base SDK' setting in the build options.

It will then probably build and run without errors, but there may well be warnings if the example is using old and deprecated features and even if there arent, there may be new easier or better ways of doing the same thing so I'd takes some time to read over the changes at developer.apple.com and get up to speed

The application that you have downloaded is made in the os 2.2.1 and in your application there won't be os 2.2.1, there might be 3.0 or higher version of os is available.

To run this application simply change the base sdk to 3.0 or as per the sdk available in your mac.

use following steps

1. click in target, application name.

2. press info button.

3. change the base sdk to 3.0 or higher as available with your mac and your application will run.