free vector pattern design

This chapter is the last lecture on design patterns, we will talk about the third design pattern-behavioral pattern, a total of 11 kinds: Policy mode, template method pattern, observer mode, iterative sub mode, responsibility chain mode, Command mode, Memo mode, state mode,

(Object Arg) is public void Notifyobservers () {notifyobservers (null); //Notify all observers that the observer has changed and that you can execute your Update method. A temporary array of public void Notifyobservers (Object arg) {//, which is used to keep the current state of the observer list while accessing the observer, is actually a design pattern, a memo

What is a design pattern. A simple understanding is a summary of some of the experiences that the predecessors have left behind. And then the experience called design patterns, translation is designed mode, through the use of design patterns can make our code more reusable, more maintainable, so that your code to write

-to-many relationship, and if you combine score into a student table, you must reserve the most possible fields, which can be wasteful and will be difficult to expand when you add a new course later , so the score table is generally separated out. And for Key-value type database is different, its scores field is a Bson, the Bson can have only one for_course, can also have two, three, any for_course, Its inherent pattern-

Learning Bridge design pattern from the angle of reconstruction Bridge mode is a pattern that is often applied in the actual system. It best embodies the principle of design pattern programming for interfaces, and the use of aggregation does not use the two principles of in

Python's adorner use is a very important part of the Python language, which is the embodiment of the decorative pattern in the programming pattern, and Python provides a special syntactic sugar that can be easily implemented in decorative mode.Series Articles A single-instance pattern of Python design patterns (i

1. Preface InArticleBefore getting started, I wrote some nonsense and wrote five articles about the design pattern. The following article is a periodic summary and reflection of the above five articles. First of all, I would like to thank winter-CN for pointing out one error after another in the design mode application. Without him, I

objects referenced by the object being copied. Advantages and disadvantages of the original model pattern Advantages:　　1. The original model model mode allows to dynamically increase or decrease the product class. Because the method of creating a product class instance is internal to the product class, adding new products has no effect on the entire structure.2. The original model mode provides a simplified creation structure. The facto

conforms to the tree structure. This pattern can be considered. This mode describes the security and transparency methods. Security: Abstract components only provide a common method of leaves and branches, do not provide a unique management of the branches and other methods (add (), remove ()). The benefit is security, the user does not use the Add () management method on the leaves, the disadvantage is not transparent enough, the user must know whet

Adapter mode is a very common pattern in software development, and the function of this mode is to enable two incompatible interfaces to work together. Most of the time we are using this pattern consciously or unconsciously. Because two interfaces are not compatible, the task of the adapter is to adapt the data or objects so that the calling interface can use the results produced by the other interface. The

Cocos observer design pattern and notification mechanism, cocos observerThe Observer (Observer) mode is also called the Publish/Subscribe mode. It is an important part of the MVC (Model-View-Controller) mode.Weather has always been a topic that British people like to discuss, and changes in weather have become a topic of great interest to Chinese people in recent years. I will decide whether to take the sub

needs to dynamically select one of several algorithms.3, if an object has a lot of behavior, if not the appropriate pattern, these behaviors have to use multiple conditional selection statements to achieve.Advantages and disadvantages of the strategy model advantages of the Strategy mode : The algorithm can switch freely, through the implementation of the abstract strategy, encapsulating the role of its encapsulation, to ensure that the extern

Factory mode is simpler and more efficient than the factory method mode when a factory hierarchy can create all objects in a product family that belong to different product hierarchy structures. The abstract factory pattern is as follows:, each specific plant can produce all products on a product family, such as squares, circles, and ellipses with the same color. These products are classified into three different product hierarchy structures. If you

method on the Count proxy object, and the Count agent performs the necessary record log (logging) and count (counting) functions, and then passes the method call to the service providing the object. As shown in Figure 1 Figure1:generic Class Association When the counting Proxy pattern is applied The following example shows how to use the Count proxy in an application. Example: Let's design an order c

Template mode The template design pattern creates an abstract object that implements a set of methods that the subclass typically uses as a template for its own design. Design Scenarios Typically used for database abstraction classes. Code Design: [PHP] if (!defined (' is

Quote a Passage：GoF (Gang of four, foursome, "design patterns:elements of reusable object-oriented Software"/"Designing Mode" a book of Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides, does not refer to MVC as a design pattern, but rather as a set of classes for building user interfaces. in their view, it is actually the evolution of the other three clas