Hands-On Design Patterns with C# and .NET Core

Decorator patterns

To illustrate a structural pattern, let's take a closer look at the Decorator pattern by using an example. This example will print messages on a console application. First, a base message is defined with a corresponding interface:

interface IMessage{    void PrintMessage();}abstract class Message : IMessage{    protected string _text;    public Message(string text)    {        _text = text;    }    abstract public void PrintMessage();}

The base class allows for the storage of a text string and requires that child classes implement the PrintMessage() method. This will then be extended into two new classes.

The first class is a SimpleMessage that writes the given text to the console:

class SimpleMessage : Message{ public SimpleMessage(string text) ...