Static Constructors (C# Programming Guide)
A static constructor is used to initialize any static data, or to perform a particular action that needs performed once only. It is called automatically before the first instance is created or any static members are referenced.
class SimpleClass
{
// Static constructor
static SimpleClass()
{
//...
}
}
Static constructors have the following properties:
A static constructor does not take access modifiers or have parameters.
A static constructor is called automatically to initialize the class before the first instance is created or any static members are referenced.
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.
Example
In this example, the class Bus has a static constructor and one static member, Drive(). When Drive() is called, the static constructor is invoked to initialize the class.
public class Bus
{
// Static constructor:
static Bus()
{
System.Console.WriteLine("The static constructor invoked.");
}
public static void Drive()
{
System.Console.WriteLine("The Drive method invoked.");
}
}
class TestBus
{
static void Main()
{
Bus.Drive();
}
}
Output
The static constructor invoked.
The Drive method invoked.
See Also
Reference
Objects, Classes and Structs (C# Programming Guide)
Destructors (C# Programming Guide)