Hình 1-6 minh họa các lớp học tập trung vào các dịch vụ hệ thống điều hành, hoạt động tập tin, và quá trình liên-truyền thông (IPC).Như hình 1-6. Hệ điều hành dịch vụ: hoạt động, hoạt động tập tin, truyền thông interprocess | Simpo PDF Merge and Split Unregistered Version - http XML I NSObịect I I NSXMLParser I Strings __ I NSObiect I I NSStrinq I I NSMutableStrinq I I NSAttributedStrinq I I NSMutableAttrbutedStrinq I I NSCharacterSet I NSMutableCharacterSet I NSFormatter I I NSDateFormatter I NSNumberFormatter I NSScanner I I NSSortDescriptor I Figure 1-4. XML and strings Collections I NSObiect I rNSArray I I NSMutableArrav I I NSDictionary I I NSMutableDictionary I I NSEnumerator I rNSPirectoryEnumerator I I NSHashTable I I NSIndexPath I r NSIndexSet I I NSMutablelndexSet I I NSMapTable I NSPointerArrav I r NSPointerFunctions NSSet I I NSMutableSet I I NSCountedSet I Figure 1-5. Collections 6 Chapter 1 Cocoa Touch The Core iPhone Download at Simpo PDF Merge and Split Unregistered Version - http Figure 1-6 illustrates classes that focus on operating system services file operations and inter-process communication IPC . Operating System Services Operations I NSObịect 1 I NSError I I NSHost I I NSNetService I I NSNetServiceBrowser I I NSProcessInfo I I NSRunLoop I I NSTimer I I NSUserDefaults I File System I NSObiect I NSBundle I NSFileHandle I I NSFileManaqer I I NSStream I I NSInputStream I rNSOutputStream I Interprocess Communication I NSObiect I NSPipe I I NSPort I I NSMachPortl I NSMessagePort I Figure 1-6. Operating system services operations file operations interprocess communication Figure 1-7 illustrates the portion of Foundation that provides for URL handling functionality. Hybrid web Cocoa applications use URL handling classes heavily. Figure 1-8 shows the classes used to manage threading in Cocoa applications. Careful thread management can be an important part of optimizing the perception of responsiveness in an application. Mac Frameworks 7 Download at Simpo PDF Merge and Split Unregistered Version - http Operating System Services Continued URL Handling I NSObịect I .