比较感兴趣的是后面的参数 kcFBundleVersionKey ,竟然是CFBundle.h已经定于好的属性，下面有这个属性的注释
const CFStringRef kCFBundleVersionKey;
/* The version number of the bundle. For Mac OS 9 style version numbers (for example "2.5.3d5"), */
/* clients can use CFBundleGetVersionNumber() instead of accessing this key directly since that */
/* function will properly convert the version string into its compact integer representation. */
还有好多是kcFXXX开头的Standard Info.plist keys 属性，有兴趣可以自己看一下CFBundle.h，研究一下它们的用法，