We learned in the Protocol-Oriented Programming session at WWDC 2015 that Swift uses two different dispatch mechanisms for methods in protocol extensions.   Methods that are protocol requirements — that is, they are declared in the protocol itself —…

8.多态Polymorphism,向上转型Upcasting,动态方法调度(dynamic method dispatch) 什么叫多态?简言之,马 克 - t o - w i n:就是父类引用指向子类时,父类和子类必须同时拥有某个同名函数,父类引用到底指向谁(调用谁的函数),是在runtime时决定的,因此呈现多种状态(不知道会指向若干子类中的哪一个还是父类自己).拿上一节的例子来讲,比如运行时如果用户输入自行车,就执行自行车的驾驶方法.如果用户输入小轿车,就执行小轿车的驾驶方法, 涉及到用户…

In this example: protocol MyProtocol { func testFuncA() } extension MyProtocol { func testFuncA() { print("MyProtocol's testFuncA") } } class MyClass : MyProtocol {} let object: MyClass = MyClass() object.testFuncA() static dispatch is used. The…

In this example: protocol MyProtocol { func testFuncA() } extension MyProtocol { func testFuncA() { print("MyProtocol's testFuncA") } } class MyClass : MyProtocol {} let object: MyClass = MyClass() object.testFuncA() static dispatch is used. The…

For every object that can have a delegate, there is a corresponding protocol that declares themessages that the object can send its delegate. The delegate implements methods from the protocol forevents it is interested in. When a class implements met…

今天看jcvm的标准的 时候,看到有一个virtual method,感觉很疑惑,以前看Java的时候并没有发现有这类方法. 百度.Google了一下,才发现,Java中普通方法就是virtual method,动态绑定是Java的默认行为. 如果不想让一个方法成为virtual method,只要把这个方法申明为final就可以了. 至于在c++中虚方法是怎么回事,可以参考下面这篇文章 http://www.cnblogs.com/xd502djj/archive/2010/09/22/183…

  15.12.1. Compile-Time Step 1: Determine Class or Interface to Search   The first step in processing a method invocation at compile time is to figure out the name of the method to be invoked and which class or interface to check for definitions of m…

1.什么是protocol? protocol(协议)是用来定义对象的属性和行为,用于回调. 2.protocol分类? 协议中有三个修饰关键字@required和@optional和@property. 3.三个修饰关键字的作用 被@required修饰的方法为必须实现的方法: 被@optional修饰的方法为可选实现的方法: @property用于修饰属性. 一.定义一个protocol 新建文件的时候不要选择objective-c Class:而要选择objective-c protoco…

Dynamic dispatch动态调度.动态分发 In computer science, dynamic dispatch is the process of selecting which implementation of a polymorphic operation (method or function) to call at run time. It is commonly employed in, and considered a prime characteristic of…

swift面向协议编程的根本原因在于值类型的存在:面向对象必须要有引用类型的支持: Protocol Oriented approach was introduced to resolve some issues in programming and it also differs in various scenarios when compared to Object-Oriented programming. So let’s dive into the topic. What is Pro…