Programming iOS 6, 3rd Edition

Sample Code

Apple provides plenty of sample code projects. You can view the code directly in the documentation window; sometimes this will be sufficient, but you can see only one class implementation or header file at a time, so it’s difficult to get an overview. The alternative is to open the sample code project in Xcode.

When you look at a sample code page from your browser, there’s a button that reads Download Sample Code. In fact, the sample code may already be on your computer. When you look at the same sample code page in the documentation window, the same button will read Open Project. The sample code on your hard disk is zipped, so even if the code is already on your computer, it is first unzipped (into your Downloads folder). This policy of keeping the sample code projects zipped on your hard disk is a good one, as it prevents you from accidentally altering the original, and you are free to experiment with the unzipped copy.

Warning

If a sample code project was linked against the frameworks of an older SDK that isn’t installed on your computer, the project will be described in the Project navigator with the words “missing base SDK.” In earlier versions of Xcode, this situation could prevent you from building and running the project, and features that depend on indexing might not work. In Xcode 4.2 and later, however, the project should build and run regardless. To remove the “missing base SDK” annotation, edit the target, switch to Build Settings, and change the outdated Base ...