在Obj-c中有静态Initialize
方法,该方法在第一次使用该类时被调用,无论是静态还是实例。在C#中有类似的东西吗?
答案 0 :(得分:3)
您可以使用与普通构造函数相同的语法编写静态构造函数,但使用static
修饰符(并且没有访问修饰符)除外:
public class Foo {
static Foo() {
// Code here
}
}
通常你不需要这样做,但是 - 静态构造函数用于初始化,通常只能在静态字段初始化器中执行:
public class Foo {
private static readonly SomeType SomeField = ...;
}
如果你使用静态构造函数做的不仅仅是初始化静态字段,那么通常一种设计气味 - 但并非总是如此。
请注意,存在静态构造函数subtly affects the timing of type initialization,要求在第一次使用之前执行 - 在第一次静态成员访问时或第一次实例之前创建,以先发生者为准。
答案 1 :(得分:2)
有一个static
构造函数。根据{{3}}:
A static constructor is used to initialize any static data, or to perform a particular action that needs to be performed once only. It is called automatically before the first instance is created or any static members are referenced.
公共课Foo { static Foo(){} //静态构造函数 }
答案 2 :(得分:-2)
是的,它被称为constructor。
通过MSDN:
public class Taxi
{
public bool isInitialized;
//This is the normal constructor, which is invoked upon creation.
public Taxi()
{
//All the code in here will be called whenever a new class
//is created.
isInitialized = true;
}
//This is the static constructor, which is invoked before initializing any Taxi class
static Taxi()
{
Console.WriteLine("Invoked static constructor");
}
}
class TestTaxi
{
static void Main()
{
Taxi t = new Taxi(); //Create a new Taxi, therefore call the normal constructor
Console.WriteLine(t.isInitialized);
}
}
//Output:
//Invoked static constructor
//true