Objective-C

In this paper, the definition and usage of the structural body nsrange,nspoint,nssize (cgsize) and Nsrect in Objective-c are described in detail, as follows: 1, Nsrange: Nsrange's prototype is typedef struct _NSRANGE { nsuinteger location;

In objective-c, sending messages to nil is not crash. The reason is that when the execution ID objc_msgsend (id self, SEL op, ...) method, if self = nil, the function does not perform any meaningful action and returns directly. The return value

1, NSString converted into nsdate NSString *datestr = "2013-6-3 14:58:00"; NSDateFormatter *format=[[nsdateformatter alloc] init]; [Format setdateformat:@ "Yyyy-mm-dd HH:mm:ss"]; NSDate *date=[format DATEFROMSTRING:DATESTR];

• Inheritance is one of the important concepts of object-oriented, and subclasses can inherit certain methods and member variables of the parent class. Member variables that have a scope qualifier of private are not inheritable. The child can also

Objective-c is a simple, powerful and flexible programming language with both object-oriented features and functional programming features. Because it is a C-language vest, that is, objective-c can convert its source code into a pure C language and

I. Archiving and unarchiving in the nscoding agreement(1) Archiving an object that will record all properties of this object to filesystem;(2) unarchiving an object and re-creates the object from data.The strength of the class to archiving and

Understanding Method Swizzling is a good opportunity to learn the runtime mechanism. Not much to do in this, only translated by Mattt Thompson published in Nshipster's method swizzling article.Method Swizzling is a technique that changes the actual

The protocol in OC is similar to the excuse of Java The Protocol is special.ProgramDesign Patterns are used to declare methods implemented by other classes. Protocols are useful in the following scenarios: 1. There must be other class

Reference: http://hi.csdn.net/hou_cocoa Cocoa It is a native compiling environment on Mac OS X. It contains two frameworks, namely a series of class libraries, foundation and appkit. On your iPhone and other handheld devices, the app uses a

Using Arc can help us reduce a lot of memory management burden, especially when we use JavaProgramPersonnel. However, I am not a strong Java Foundation. After two years of development, IOS has become accustomed to manual memory management, and arc

Method for creating nsstring: Nsstring * str1 = @ "Hello World ";Nsstring * str2 = [[nsstring alloc] init];Str2 = @ "Hello World ";[Str2 release]; Nsstring * str3 = [[nsstring alloc] initwithstring: @ "Hello World"];[Str3 release]; // The memory

common methods for creating nsdictionary: + (ID) dictionary; + (ID) dictionarywithobjtct :( ID) object forkey :( id ) Key; + (ID) dictionarywithobjectandkeys :( ID) firstobject ,... + (ID) dictionarywithdictionary :( nsdictionary *

The basics of objective-C are supported by the GNU Compiler Collection. in order to utilize the full power of objective-C together with the cocoa/openstep environments on Linux, and to work with privileges of the examples covered in this book, it is

To use the prompt function of xcode, you only need to remember the class name and common functions. Other functions can be viewed as prompted. Press ESC to view functions of this class. Foundtion framework The cocoa program mainly uses two

Object archiving refers to writing an object into a file and saving it on the hard disk. When the program is blocked again, these objects can be restored. Object archiving is also called object serialization or object persistence. Persistent storage

Blogger: Yi Feifei Link: http://www.yifeiyang.net/iphone-development-advanced-1-depth-understanding-of-iphone-os-sdk-and-objective-c-2-0/ Reprinted text.Advanced iPhone development (1) --- in-depth understanding of iPhone OS/SDK and objective-C 2.0

1 ID cattle [3];2 sel say;3 sel skin; The ID cattle [3] defines an array used to store cattle or bull objects. This line of code is probably quite familiar to everyone, so I will not go into details here. Traditional arrays like this cannot fully

Class type So far, we have known the SEL data type corresponding to the method. Like Sel, in objective-C, we can not only use the SEL corresponding to the method, for Classes in objective-C, a similar mechanism is also provided for us, class type.

It is not terrible for iPhone objective-C exc_bad_access to write programs with bugs. For most problems, it is not difficult to find the cause through simple log or code analysis. However, when the problem of exc_bad_access is encountered in

Objective-C syntax for object objects If the original Yusong Momo article is reprinted, please note: It is reprinted to my independent domain name blogYusong Momo program Research Institute, Original address: http://www.xuanyusong.com/archives/401