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。据我了解，静态字段会在程序执行期间保留该值。

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，提出了一些建议的更改：

将类设为静态
摆脱构造函数，因为静态类不能具有实例构造函数。

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;
        }
    }
}

Answer 2

因为您在构造函数方法中设置了MaxAttempts，WarningAttempts，Threshold字段。

使用AttemptController Obj = new AttemptController(3, 2);时将设置该值。

使用时将设置MaxAttempts = 3和WarningAttempts = 2

AttemptController Obj = new AttemptController(3, 2);

使用时将设置MaxAttempts = 7和WarningAttempts = 5

AttemptController Obj1 = new AttemptController(7, 5);

static字段允许所有实例使用相同的字段值。

以下示例代码中AttemptController中静态字段的含义是什么？

2 个答案: