Emit Learning-Basic articles-helloworld

In accordance with the industry's practice, we use one of the simplest examples-"Hello world"-to begin our emit journey. The relevant code and comments for the example are as follows:

 using System;

Using System.Collections.Generic;

Using System.Text;


Using System.Reflection.Emit;

　　　　　　　 Namespace Emitexamples.helloworld {class Program {///<summary>///a delegate to invoke a dynamic method


　　　　　　　 </summary> Private delegate void Helloworlddelegate (); static void Main (string[] args) {//define a dynamic method named HelloWorld, no return value, no parameter DynamicMethod hell


　　　　　　　　　　　 Oworldmethod = new DynamicMethod ("HelloWorld", NULL, NULL);

　　　　　　　　　　　 Create an MSIL generator to generate code for the dynamic method ILGenerator Helloworldil = Helloworldmethod.getilgenerator ();

　　　　　　　　　　　 The Hello world! word that will be output is Fuganga loaded onto the stack helloworldil.emit (opcodes.ldstr, "Hello world!");

　　　　　　　　　　　 Call Console.WriteLine (string) method output Hello world! Helloworldil.emit (Opcodes.call, typeof (Console).

　　　　　　　　　　　 GetMethod ("WriteLine", new type[] {typeof (String)}));

　　　　　　　　　　　 Method ends, returns Helloworldil.emit (Opcodes.ret); Completes the creation of the dynamic method, and gets the one that can execute the dynamic sideThe commission of the law helloworlddelegate HelloWorld = (helloworlddelegate) helloworldmethod.createdelegate (typeof (Helloworlddel

　　　　　　　　　　　 egate));

　　　　　　　　　　　 Executes the dynamic method that will print the Hello world! on the screen

　　　　　　　 HelloWorld (); }} 

Here we just use this example to give you an intuitive understanding of emit and IL, and the methods used will be specifically explained in later chapters

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