简单的说一下，一个class含两个enum，然后新建一个2维class数组，给数组付值时nullReferenceException错误。

找到错误原因了。

错误原因:
C#中，如果数组中的元素是引用类型，则需要为每个元素分配内存空间。也就是说，new一次数组之外，还需要new每个元素。
 

public enum Show
        {
            Bomb = -3,
            Blank = -2,
            FLAG = -1,
            Zero = 0,
            One = 1,
            Two,
            Three,
            Four,
            Five,
            Six,
            Seven,
            Eight,
 
        }
        public enum IsMine
        {
            Mine,
            NotMine
        }

 public class gridstatus
        {
            public Show show{get;set;}
            public IsMine ismine{get;set;}
 
        }
 
        public gridstatus[,] grid = new gridstatus[9, 9];

 public void newGame()
        {
            //grid[0, 0].show = Show.Blank;
 
            foreach (var a in grid)
            {
                a.show = Show.Blank;//这里出现nullReferenceException错误
                //a.show = (Show)1;
                ///TODO
                Random ra = new Random();
                int t = ra.Next(10);
                if (t < 2)
                {
                    a.ismine = IsMine.Mine;
                }
                else
                {
                    a.ismine = IsMine.NotMine;
                }
 
            }


[ 本帖最后由 adbest 于 2013-8-2 15:14 编辑 ]

这个只是一个程序的一部分。我简化了下代码，帮忙看看，先谢谢了。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
             number[] t= new number[9];
             foreach (var k in t)
             {
                 k.a = 1;//这里出现nullReferenceException错误
                 k.b = 1;
             }
             Console.WriteLine(t[5].a);
        }
        public  class number
            {
                public int a{get;set;}
                public int b{get;set;}
            }
        
        
    }
}