Static Constructor

performed once only. 

It is called automatically before the first instance is created or any static members are referenced.

• A static constructor does not take access modifiers or have parameters.
• A static constructor cannot be called directly.
• The user has no control on when the static constructor is executed in the program.
• A typical use of static constructors is when the class is using a log file and the constructor is used to write entries to this file.
• Static constructors are also useful when creating wrapper classes for unmanaged code, when the constructor can call the LoadLibrary method.
• If a static constructor throws an exception, the runtime will not invoke it a second time, and the type will remain uninitialized for the lifetime of the application domain in which your program is running

public class MyClass

 {

     public MyClass()

     {

         Console.WriteLine("Is Class Constructor");

     }

     static MyClass()

     {

         Console.WriteLine("Is Static Constructor");

     }

     public void method()

     {

         Console.WriteLine("Method A");

     }

     public static void methodStatic()

     {

         Console.WriteLine("Method Static");

     }

 }

 static void Main(string[] args)

 {

     MyClass classA = new MyClass();

     MyClass classB = new MyClass();

     classA.method();

     classB.method();

     MyClass.methodStatic();

     Console.ReadLine();

 }

Result :

Is Static Constructor

Is Class Constructor

Is Class Constructor

Method A

Method A

Method Static