c# - 以下示例代码中 AttemptController 中的静态字段是什么意思？

Question

我是 C# 的新手，正在尝试学习 static 关键字。我不明白为什么我们需要两次初始化静态字段。根据我的理解，静态字段在程序执行期间保留值。

class Program
    {
        static void Main(string[] args)
        {

        AttemptController Obj = new AttemptController(3, 2);
        Console.WriteLine("Maximum:   {0}", AttemptController.MaxAttempts);
        Console.WriteLine("Warning:   {0}", AttemptController.WarningAttempts);
        Console.WriteLine("Threshold: {0}", AttemptController.Threshold);

        AttemptController Obj1 = new AttemptController(7, 5);
        Console.WriteLine("Maximum:   {0}", AttemptController.MaxAttempts);
        Console.WriteLine("Warning:   {0}", AttemptController.WarningAttempts);
        Console.WriteLine("Threshold: {0}", AttemptController.Threshold);
        Console.ReadLine();
    }

    class AttemptController
    {
        internal static int MaxAttempts;
        internal static int WarningAttempts;
        internal static int Threshold;

        public AttemptController(int a, int b)
        {
            MaxAttempts = a;
            WarningAttempts = b;
            Threshold = MaxAttempts - WarningAttempts;
        }
    }
}

Answer 1

因此，提出了一些更改建议:

• 使类静态化
• 去掉构造函数，因为静态类不能有实例构造函数。

• 添加一个名为 init 的新方法，仅用于演示目的。

  using System;
  
  namespace ConsoleApp4
  {
      internal class Program
      {
          private static void Main(string[] args)
          {
              AttemptController.Init(3, 2);
              Console.WriteLine("Maximum:   {0}", AttemptController.MaxAttempts);
              Console.WriteLine("Warning:   {0}", AttemptController.WarningAttempts);
              Console.WriteLine("Threshold: {0}", AttemptController.Threshold);
  
              AttemptController.Init(7, 5);
              Console.WriteLine("Maximum:   {0}", AttemptController.MaxAttempts);
              Console.WriteLine("Warning:   {0}", AttemptController.WarningAttempts);
              Console.WriteLine("Threshold: {0}", AttemptController.Threshold);
              Console.ReadLine();
      }
  }
  
      public static class AttemptController
      {
          internal static int MaxAttempts;
          internal static int WarningAttempts;
          internal static int Threshold;
  
  
  
          public static void Init(int a, int b)
          {
              MaxAttempts = MaxAttempts + a;
              WarningAttempts = WarningAttempts + b;
              Threshold = MaxAttempts - WarningAttempts;
          }
      }
  }