通用静态字段初始化 [英] Generic static fields initialization

问题描述

  public static class Container< T> 
 {
 public static readonly T [] EmptyArray = new T [0]; 
} 
  

正如我已经理解静态类Container将在下面的代码时被初始化执行：

  ... 
 var emptyArray = Container< int> .EmptyArray; 
 ... 
  

我是对吗？赞赏静态泛型类/成员初始化的任何解释。提前致谢。

解决方案

保证是静态字段在您访问它之前被初始化。 （另外，如果还有一个静态构造函数，那么在静态构造函数运行之前，所有静态字段都将被初始化。）对于泛型类，静态初始化可以工作每个类型的基础，所以 Container< int> 就好像它是一个完全不同于 Container< double> 。这对于泛型类的所有静态部分都是如此 - 每种类型都有自己的'复制'。

一个例子会更清楚地显示最后一点：

  static class Foo< T> 
 {
 static int count = 0; 
 public static int Increment（）
 {
 return ++ count; 
 
 
 
 public class Program 
 {
 public static void Main（）
 {
 Console.WriteLine（Foo< ; INT> .Increment（））; 
 Console.WriteLine（Foo< int> .Increment（））; 
 Console.WriteLine（Foo< double> .Increment（））; 
 
 
 $ / code $ / pre 
 $ b $输出：
 
 
  1 
 2 
 1 
  
 
I'm just getting curious about the following code :
public static class Container<T>
{
    public static readonly T[] EmptyArray = new T[0];
}
As I've understood the static class Container will be initialized when the following code executes:
...
var emptyArray = Container<int>.EmptyArray;
...
Am I right ? Any explanations on static generic classes/members initialization would be appreciated. Thanks in advance.
解决方案
The guarantee is that the static field is initialized before you access it. (And also, if there is also a static constructor, then all static fields will be initialized before the static constructor is run.)

For generic classes, static initialization works on a per-type basis, so Container<int> acts as if it is a completely different class to Container<double>. This is actually true for all static parts of a generic class - each type gets its own 'copy'.

An example will show this last point more clearly:
static class Foo<T>
{
    static int count = 0;
    public static int Increment()
    {
        return ++count;
    }
}

public class Program
{
    public static void Main()
    {
        Console.WriteLine(Foo<int>.Increment());
        Console.WriteLine(Foo<int>.Increment());
        Console.WriteLine(Foo<double>.Increment());
    }
}
Output:
1
2
1


                        
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