无法通过NullReferenceException

本文关键字：NullReferenceException | 更新日期: 2023-09-27 18:28:58

我是编程新手，尤其是c#。我已经写了一些代码，但在运行时不断出现错误，在修复之前我无法继续前进。

有问题的错误是NullReferenceException。它还告诉我"对象引用没有设置为对象的实例"。

这似乎是一条非常清晰的错误消息，指示对象尚未实例化。然而，我以为我已经做到了。我希望有人能向我解释我做错了什么。这是我的密码。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
namespace EvenHelemaalOvernieuw
{
    class Globals
    {
        public static int size = 50;
        public static int factor = 3;
        public static int puzzleNumber = 1;
        public static Square[,] allSquares = new Square[Globals.factor * Globals.factor, Globals.factor * Globals.factor];
        public static String path = @"" + factor.ToString() + "''" + puzzleNumber.ToString() + ".txt";
        public static int[,][,] values = new int[factor, factor][,];
        public Globals() { }
        public void setSize(int s)
        {
            size = s;
            if (size > 100)
            {
                size = 100;
            }
            if (size < 20)
            {
                size = 20;
            }
        }
        public void setFactor(int f)
        {
            factor = f;
            if (factor > 5)
            {
                factor = 5;
            }
            if (factor < 2)
            {
                factor = 2;
            }
        }
        public Square getSquare(int x, int y)
        {
            return allSquares[x, y];
        }
        public static void readPuzzle()
        {
            List<int> conversion = new List<int>();
            int count = 0;
            using (StreamReader codeString = new StreamReader(path))
            {
                String line = codeString.ReadToEnd();
                Array characters = line.ToCharArray();
                foreach (char a in characters)
                {
                    if (a.ToString() != ",")
                    {
                        conversion.Add(Convert.ToInt32(a));
                    }
                }
                for (int panelX = 0; panelX < factor; panelX++)
                {
                    for (int panelY = 0; panelY < factor; panelY++)
                    {
                        for (int squareX = 0; squareX < factor; squareX++)
                        {
                            for (int squareY = 0; squareY < factor; squareY++)
                            {
                                values[panelX, panelY][squareX, squareY] = conversion[count];
                                count++;
                            }
                        }
                    }
                }
            }
        }
   }
}

错误消息指示的行位于底部附近，读取values[panelX, panelY][squareX, squareY] = conversion[count];。

无法通过NullReferenceException

问题出在以下行

public static int[,][,] values = new int[factor, factor][,];

这是一个数组数组，但此代码只创建外部数组。内部数组未初始化，将为null。因此，当以下代码运行时，它将抛出一个NullReferenceException，试图访问内部阵列

values[panelX, panelY][squareX, squareY] = conversion[count];

要解决此问题，只需在第三个嵌套循环之前初始化数组元素

values[panelX, panelY] = new int[factor, factor];
for (int squareX = 0; squareX < factor; squareX++)
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