notification system design patterns

iOS development learning, often do not understand the development model of iOS, today we will be a simple summary and discussion ~(a) Agent modeScenario: When some functionality of a class needs to be implemented by another class, it is not certain which class implementation is specific.Advantages: DecouplingAgile principle: open-closed principleExample: TableView data source delegate, through and protocol cooperation, complete the request.List row number delegateCustom delegate(ii) Observer pat

. NET domain driven design-first taste (one: questions, patterns, principles, tools, processes, frameworks, practices)2013-04-07 17:35:27Tags:. NET DDD Driver Design original works, allow reprint, please be sure to use hyperlinks in the form of the original source of the article, author information and this statement. Otherwise, the legal liability will be invest

to understand, and ensure code reliability. There is no doubt that the design model is a win-win solution for others and the system. The design model enables code compilation to be truly engineered. The design model is the foundation of software engineering, just like the building blocks. Gof's "

Tag: Java logs this dependent for Code mode packThe observer pattern for Java design patternsHave always wanted to write a study of the Observer Pattern Summary no opportunity, today learning to block the principle of the queue to see in the implementation of the producer consumer when the notification mode, is the so-called observer mode, just by the way to tidy up a bit.1. IntroductionThe Observer pattern

1, what is the design modeWith regard to design patterns, there are some more official definitions, such as: Design pattern is a set of reusable, most known, categorized purposes, code design experience Summary. Design

all, there are multiple inheritance relationships, and as the concrete implementation increases, the inheritance of subclasses becomes very complicated, and secondly, if there are new abstractions or new concrete implementation roles, we have to re-modify the static relationship in the existing system to adapt to the new role. This violates the open-closed principle. The correct design should be to use two

The Observer PatternThe Observer is a design pattern where an object (known as a subject) maintains a list of objects depending on it (observe RS), automatically notifying them of any changes to the state.When a subject needs to notify observers on something interesting happening, it broadcasts a notification to the Observ ERS (which can include specific data related to the topic of the

returnSingle ; One } A}A Hungry Man sample code:1 Public classSingleton {2 PrivateSingleton () {}3 Private Static FinalSingleton single =NewSingleton (); 4 Public StaticSingleton getinstance () {5 returnSingle ; 6 } 7}Lazy Thread-safety improvements, Method 1:1 Public classSingleton {2 //privatization default constructor3 PrivateSingleton () {}4 Private StaticSingleton single=NULL; 5 //static Factory method (plus synchronous method)

patterns How to solve design problems:(1) Finding the right objectA customer request is the only way to make an object perform an action that is the only way an object changes internal data.The most difficult part of object-oriented is the decomposition of the system into a collection of objects, because there are a number of factors to consider: encapsulation,