notification system design patterns

Learning C # design patterns series notes (2) Observer patterns, I. References 1. Head First Design Patterns (Chinese name: deep dive into Design Patterns) 2. Wikipedia, observer mode,

Through the mobile phone notification system, you can inform the user of some important information about the application. Fluent, comfortable, and friendly applications are inseparable from well-designed message alerting mechanisms. But not all of the notices are users want to see, otherwise it will only cause harassment to users, so be cautious to use the notice. In translation of the Android

This article references:: Geekband classroom content, Instructor: Li Jianzhong: Network information: http://blog.csdn.net/hguisu/article/details/7556625This article only as own study note, does not represent the authority, because is the beginner, has the mistake to please everybody correct, thanks.1, what is the Observer mode, where are the application sites?The Observer pattern (sometimes called the publish-subscribe subscribe> mode, model-view view> mode, source-listener listener> mode, or sl

This article continues to introduce23 Design Mode SeriesThe Observer pattern. definitionIn the process of software building, the internal structure of collection objects often varies, but for these collection objects, we want to allow external client code to transparently access the elements contained therein while not exposing its internal structure, and this "transparent traversal" also provides the possibility for the same algorithm to operate on a

: Used to remove their own registration; Do not rely on the order in which the observers are notified: since the purpose of our design is loosely coupled, if subject makes some changes that cause the order of the notifications to change, if there is some sort of dependency on the notification order in Obsever, Then observer must also make corresponding changes to adapt to subject changes, which is not i

Five common PHP design patterns-the factory model. Five common design patterns in PHP-the factory model has always had a sense of reverence for the design patterns. every time you want to see the

Context.getsystemservice to obtain a system service management object, it first obtains the corresponding Servicefetcher object from the Map collection based on the service name , and then calls The GetService function of the Servicefetcher object obtains the service management object created by the Servicefetcher object. In the getservice function of the Servicefetcher object, first from the list of cache arrays maintained by the context, find if t

the chain, and a request may not be processed because the responsibility chain is not properly configured. (2) for a longer chain of responsibility, the processing of the request may involve multiple processing objects, the system performance will be affected, and the code debugging is not very convenient. (3) If the chain is improperly built, it can cause cyclic calls, which will cause the system to fall

I. OverviewIn software design work there is a dependency between objects, and when an object changes, all objects that depend on it need to be notified. If the design is not good, it is easy to cause the coupling between the object is too high, difficult to cope with the change. Using the Observer pattern reduces the dependency between objects and achieves this in a loosely coupled manner.Second, the Observ

. Attributes that fall into this category include: Constructor constructors, factory factories, abstract abstractions, prototype prototypes, singleton single cases, and builder generators Structural design pattern Structured patterns are related to object composition and can often be used to find simple ways to establish relationships between different objects.The pa