代码（1）

 int[] nums = new int[10]; int[] count = new int[4];
 try
 {
     for (int i = 0; i < nums.Length; i++)
     {
         Console.Write("请输入第{0}个数字",i+1);
         nums[i] = Convert.ToInt32(Console .ReadLine());
         if (nums [i]==1)
         {
             count[0]++;
         }
         else if (nums [i]==2)
         {
             count[1]++;
         }
         else if (nums [i]==3)
         {
             count[2]++;
         }
         else 
         {
             count[3]++;
         }
     }
     Console.WriteLine("数字1的个数为：{0}",count[0]);
     Console.WriteLine("数字2的个数为：{0}", count[1]);
     Console.WriteLine("数字3的个数为：{0}", count[2]);
     Console.WriteLine("非法数字的个数为：{0}", count[3]);
 }
 catch 
 {
     Console.WriteLine("输入有误，请重新输入！");
 }
 Console.ReadKey();

代码（2）

        int[] nums = new int[10]; int[] count = new int[4];
        try
        {
            for (int i = 0; i < nums.Length; i++)
            {
                Console.Write("请输入第{0}个数字：",i+1);
                nums [i] = Convert.ToInt32(Console.ReadLine());
                switch (nums[i])
                {
                    case 1:
                        count[0] += 1;
                        break;
                    case 2:
                        count[1] += 1;
                        break;
                    case 3:
                        count[2] += 1;
                        break;
                    default:
                        count[3] += 1;
                        break;
                }
            }
            Console.WriteLine("数字1的个数为：{0}", count[0]);
            Console.WriteLine("数字2的个数为：{0}", count[1]);
            Console.WriteLine("数字3的个数为：{0}", count[2]);
            Console.WriteLine("非法数字的个数为：{0}", count[3]);
        }
        catch
        {
            Console.WriteLine("输入有误，请重新输入！");
        }
        Console.ReadKey();

效果

image.png