Introduction - If you have any usage issues, please Google them yourself
23 design patterns plus sample code (C# Implementation), Design Pattern is a set of repeated, most people aware, classified, code design experience summary.
The purpose of using design patterns: to code reusability, to make code easier for others to understand, and to ensure code reliability. Design patterns make code writing really engineering; design patterns are the bedrock of software engineering, just like the structure of a building