[You must know. NET] The 23rd time: taste details, in-depth. NET's type Builder

1 Introduction

Today, Artech on the question of type initializer and beforefieldinit, and see if you can give us the correct explanation, we know an interesting example of the execution of a type constructor call. In this paper, we also propose some discussion about the timing of beforefieldinit for type constructors, which is a good practical experience for us to understand the type builder.

As a supplement, this article hopes to start from the basis of further layers, the "questions about type initializer and beforefieldinit, see if we can give the correct explanation" in the article does not explain the concept and principle, to carry out the necessary supplements, such as a more comprehensive understanding of type Builder, Know BeforeFieldInit. On this basis, we discuss a bit about the practical application of the type constructor and expect to be able to answer the results of the example run.

Cut the crap, we start.

2 Understanding object Constructors and type constructors

In. NET, the initialization process for a class is done in the constructor. And depending on the type of the constructed member, is divided into type constructors (. cctor) and Object Constructors (. ctor), where. cctor and. ctor are represented by the two directives in the IL code. cctor can not be directly called, its calling rules is the focus of this article, see the analysis of the following text , and. ctor is invoked automatically when the type is instantiated.

Based on the discussion of type constructors, it is necessary to first implement a simple class definition, which includes ordinary constructors and static constructors, such as

//　Release　:　code01,　2008/11/02

　　 //　Author　:　Anytao,　http://www.anytao.com

　　 public　class　User

　　 {

　　　　 static　User()

　　　　 {

　　　　　　 message　=　"Initialize　in　static　constructor.";

　　　　 }

　　　　 public　User()

　　　　 {

　　　　　　 message　=　"Initialize　in　normal　construcotr.";

　　　　 }

　　　　 public　User(string　name,　int　age)

　　　　 {

　　　　　　 Name　=　name;

　　　　　　 Age　=　age;

　　　　 }

　　　　 public　string　Name　{　get;　set;　}

　　　　 public　int　Age　{　get;　set;　}

　　　　 public　static　string　message　=　"Initialize　when　defined.";