与抽象类类似
在 Objective-C 语言中, 如果一个类实现了一个协议的所有要求的方法我们就说它遵循一个协议。通过在类或者类别声明后面的大括号内列出协议的名字来表示它遵循一个协议。
Application Kit(应用工具包). 是一个实现了应用用户界面的 Cocoa 框架。它提供了一个基础的应用程序框架,可以用来绘制界面以及响应事件。
可以与 synchronous message (同步消息)进行对比。
Objective-C 语言中,一组与定义在类中方法隔离开的方法声明。类别可以用于将一个类的声明分割成几个部分或者为一个已经存在的类添加新的方法。
Objective-C 语言中, 某种特定类型的对象的原型。类定义声明了实例变量并为类的所有成员定义的方法。拥有相同实例变量类型并可以访问相同方法的对象属于同一个类。参见 class object.
Objective-C 语言中, 可以基于类对象操作的方法,而不是基于类的实例。
Objective-C 中的主要编程接口。
init...
负有为一个类的实例进行初始化任务的最高责任。每个类可以定义或者继承它自己指定的初始化工作。通过发消息给self
, 其它的在同一个类中的 init...
方法直接或者间接的调用指定的初始化程序, 并且初始化程序通过发消息给 super
, 会调用它的父类指定的初始化程序。
The Objective-C runtime table that contains entries that associate method selectors with the class-specific addresses of the methods they identify.
一种用于建立在C基础之上的语言的技术,操作系统会在应用运行时根据它的需要为其分配内存而不是在它启动时就分配。
—即,找到为响应消息应该调用的方法实现—运行时进行执行这项任务,而不是在编译时
而不是在编译时。
与 class object (类对象)一样
@protocol
指令声明的协议. 类可以采用一个正式协议,运行时,当对象被询问是否遵循了某个协议时,对象可以进行响应,实例则可以被赋予它们所遵循的协议作为类型
一种给相关的一组类,协议,以及方法,在线文档。。。进行打包使用的技术。 Cocoa 提供了 Foundation 框架 以及 AppKit 框架。
id
被定义为指向一个对象数据结构的指针。它可以用于类对象也可以用于类的实例。
Objective-C 类配置的一部分,定义了公有方法(定义在类的接口中的方法) 以及一些私有方法
有种协议声明成一个类别,通常是作为 NSObject
类的一个类别。本语言对正式协议有着良好的支持,但对非正式协议则没有。
在面向对象编程中,每个类 (除了根类,比如 NSObject
) 都有一个父类,并有不限个数的子类。通过它的子类,每个都都从继承关系中延续父类,父父类中的特性
. 实例在运行时根据类的声明以及定义被创建。
任何可以被类的实例使用的方法(而不是被类对象使用的那些)。
Objective-C 中类配置(定义了它的公有接口,包括它的父类名,实例变量,以及公有方法原型)的一部分
(名字) 以及陪同参数告诉消息表达式的接收对象应该做什么。
在面向对象编程时的一个表达式,它hi给一个对象发送一个消息。在 Objective-C 语言中,消息表达式是包含在一个一对中括号内,由一个接收器以及紧跟其后的消息 (方法选择器以及其参数)组成.
在面向对象编程中,一个对象可以执行的进程
mutual exclusion semaphore的缩写. 一个可以用于让线程执行同步的对象。
例如, Objective-C 中, 一个类的实例方法是在该类的唯一命名空间内。类似的,类方法则在它们自己的命名空间里,类的实例变量也在它们自己的命名空间中。
在Objective-C 语言中, 一个 id
值为 0 的对象
(实例变量) 以及操作 (方法) ,可以使用或者影响数据。对象是面向对象编程的核心。
Outlet 实例变量是一个对象可以对其它它要对其发送消息对象保持追踪的途径。
在Objective-C 中, 对一组方法的声明,没有与任何特定的类进行关联。还可以参见 formal protocol, informal protocol.
在 Objective-C 语言中, 在源码中发给一个对象的消息中的方法名,或者是在源码编译时用来替换该名字的唯一标示符。编译后的选择器的类型是 SEL
.
自别的类的类。有时候也用作动词标识定义一个类的子类的过程
asynchronous message 异步消息进行比较。
A class that’s defined solely so that other classes can inherit from it. Programs don’t use instances of an abstract class; they use only instances of its subclasses.
Same as abstract class.
In the Objective-C language, a class is said to adopt a protocol if it declares that it implements all the methods in the protocol. Protocols are adopted by listing their names between angle brackets in a class or category declaration.
An object of unknown class. The interface to an anonymous object is published through a protocol declaration.
Sometimes called Application Kit. A Cocoa framework that implements an application's user interface. AppKit provides a basic program structure for applications that draw on the screen and respond to events.
A remote message that returns immediately, without waiting for the application that receives the message to respond. The sending application and the receiving application act independently, and are therefore not in sync. Compare synchronous message.
In the Objective-C language, a set of method definitions that is segregated from the rest of the class definition. Categories can be used to split a class definition into parts or to add methods to an existing class.
In the Objective-C language, a prototype for a particular kind of object. A class definition declares instance variables and defines methods for all members of the class. Objects that have the same types of instance variables and have access to the same methods belong to the same class. See also class object.
In the Objective-C language, a method that can operate on class objects rather than instances of the class.
In the Objective-C language, an object that represents a class and knows how to create new instances of the class. Class objects are created by the compiler, lack instance variables, and can’t be statically typed, but otherwise behave like all other objects. As the receiver in a message expression, a class object is represented by the class name.
An advanced object-oriented development platform in Mac OS X. Cocoa is a set of frameworks whose primary programming interfaces are in Objective-C.
The time when source code is compiled. Decisions made at compile time are constrained by the amount and kind of information encoded in source files.
In the Objective-C language, a class is said to conform to a protocol if it (or a superclass) implements the methods declared in the protocol. An instance conforms to a protocol if its class does. Thus, an instance that conforms to a protocol can perform any of the instance methods declared in the protocol.
An object that acts on behalf of another object.
The init...
method that has primary responsibility for initializing new instances of a class. Each class defines or inherits its own designated initializer. Through messages to self
, otherinit...
methods in the same class directly or indirectly invoke the designated initializer, and the designated initializer, through a message to super
, invokes the designated initializer of its superclass.
The Objective-C runtime table that contains entries that associate method selectors with the class-specific addresses of the methods they identify.
An architecture that facilitates communication between objects in different address spaces.
A technique used in C-based languages where the operating system provides memory to a running application as it needs it, instead of when it launches.
Binding a method to a message—that is, finding the method implementation to invoke in response to the message—at runtime, rather than at compile time.
Discovering the class of an object at runtime rather than at compile time.
A programming technique that hides the implementation of an operation from its users behind an abstract interface. It allows the implementation to be updated or changed without impacting the users of the interface.
The direct or indirect report of external activity, especially user activity on the keyboard and mouse.
Same as class object.
Same as class object.
In the Objective-C language, a protocol that’s declared with the @protocol
directive. Classes can adopt formal protocols, objects can respond at runtime when asked if they conform to a formal protocol, and instances can be typed by the formal protocols they conform to.
A way to package a logically related set of classes, protocols, and functions together with localized strings, online documentation, and other pertinent files. Cocoa provides the Foundation framework and the AppKit framework, among others.
In the Objective-C language, the general type for any kind of object regardless of class. id
is defined as a pointer to an object data structure. It can be used for both class objects and instances of a class.
The part of an Objective-C class specification that defines public methods (those declared in the class’s interface) as well as private methods (those not declared in the class’s interface).
In the Objective-C language, a protocol declared as a category, usually as a category of the NSObject
class. The language gives explicit support to formal protocols, but not to informal ones.
In object-oriented programming, the ability of a superclass to pass its characteristics (methods and instance variables) on to its subclasses.
In object-oriented programming, the hierarchy of classes that’s defined by the arrangement of superclasses and subclasses. Every class (except root classes such as NSObject
) has a superclass, and any class may have an unlimited number of subclasses. Through its superclass, each class inherits from those above it in the hierarchy.
In the Objective-C language, an object that belongs to (is a member of) a particular class. Instances are created at runtime according to the specification in the class definition.
In the Objective-C language, any method that can be used by an instance of a class rather than by the class object.
In the Objective-C language, any variable that’s part of the internal data structure of an instance. Instance variables are declared in a class definition and become part of all objects that are members of or inherit from the class.
The part of an Objective-C class specification that declares its public interface, which includes its superclass name, instances variables, and public-method prototypes.
A tool that lets you graphically specify your application’s user interface. It sets up the corresponding objects for you and makes it easy for you to establish connections between these objects and your own code where needed.
The time when files compiled from different source modules are linked into a single program. Decisions made by the linker are constrained by the compiled code and ultimately by the information contained in source code.
In object-oriented programming, the method selector (name) and accompanying parameters that tell the receiving object in a message expression what to do.
In object-oriented programming, an expression that sends a message to an object. In the Objective-C language, message expressions are enclosed within square brackets and consist of a receiver followed by a message (method selector and parameters).
In object-oriented programming, a procedure that can be executed by an object.
Short for mutual exclusion semaphore. An object used to synchronize thread execution.
A logical subdivision of a program within which all names must be unique. Symbols in one namespace do not conflict with identically named symbols in another namespace. For example, in Objective-C, the instance methods of a class are in a unique namespace for the class. Similarly, the class methods of a class are in their own namespace, and the instance variables of a class are in their own namespace.
In the Objective-C language, an object id
with a value of 0.
A programming unit that groups together a data structure (instance variables) and the operations (methods) that can use or affect that data. Objects are the principal building blocks of object-oriented programs.
An instance variable that points to another object. Outlet instance variables are a way for an object to keep track of the other objects to which it may need to send messages.
In object-oriented programming, the ability of different objects to respond, each in its own way, to the same message.
A language, such as C, that organizes a program as a set of procedures that have definite beginnings and ends.
In the Objective-C language, the declaration of a group of methods not associated with any particular class. See also formal protocol, informal protocol.
In object-oriented programming, the object that is sent a message.
A memory-management technique in which each entity that claims ownership of an object increments the object’s reference count and later decrements it. When the object’s reference count reaches zero, the object is deallocated. This technique allows one instance of an object to be safely shared among several other objects.
A message sent from one application to an object in another application.
An object in another application, one that’s a potential receiver for a remote message.
The time after a program is launched and while it’s running. Decisions made at runtime can be influenced by choices the user makes.
In the Objective-C language, the name of a method when it’s used in a source-code message to an object, or the unique identifier that replaces the name when the source code is compiled. Compiled selectors are of type SEL
.
In the Objective-C language, giving the compiler information about what kind of object an instance is, by typing it as a pointer to a class.
In the Objective-C language, any class that’s one step below another class in the inheritance hierarchy. Occasionally used more generally to mean any class that inherits from another class. Also used as a verb to mean the process of defining a subclass of another class.
In the Objective-C language, a class that’s one step above another class in the inheritance hierarchy; the class through which a subclass inherits methods and instance variables.
A remote message that doesn’t return until the receiving application finishes responding to the message. Because the application that sends the message waits for an acknowledgment or return information from the receiving application, the two applications are kept in sync. Compareasynchronous message.