Archiv der Kategorie: Design Pattern

The Command design pattern encapsulates a request as an object. This will allow adding additional functionality to the request. A typical example is the undo/redo functionality. The command object will be used as mediator between the client and the receiver … Weiterlesen →

One of the five SOLID principles is Dependency Inversion. To implement according to this principle you can use interfaces and dependency injection. As a software application normally consists of hundreds or thousands of objects you will have to set up … Weiterlesen →

The composite design pattern is used to compose objects into a tree structure. So each element can hold a list of sub elements. Optional it may have a link to the parent object within the tree. Within the following example … Weiterlesen →

By using the Singleton design pattern you ensure that a class has only one instance. The instance operation is provided by the class itself. So it maintains its own unique instance. The .NET framework offers a very simple and thread-safe … Weiterlesen →

The idea of the Proxy design pattern is to provide a substitute for another object were the substitute controls the access to the other project. So there is one real subject with a given interface, for example an object to … Weiterlesen →

The Observer design pattern is used when you want to define a one-to-many dependency between objects. In case one object changes its state, all its dependents are notified and updated automatically. In this design pattern you have two participants. The … Weiterlesen →

A Façade class provides a higher level interface to a set of sub level interfaces. This will make the subsystem easier to use. The high level interface will hide details of the low level interfaces. This may be complex workflows … Weiterlesen →