C#控制台生成10个不重复随机数

求助控制台生成1-20随机数，生成10个，不能重复
var num = Enumerable.Range(1, 20)
    .Select(x => new { v = x, k = Guid.NewGuid().ToString() }).ToList()
    .OrderBy(x => x.k)
    .Select(x => x.v)
    .Take(10).ToList();
foreach (var i in num)
{
    Console.WriteLine(i);
}

for(int i=0;i<=10;i++)
{
  Random Rdm = new Random(); 
  int iRdm = Rdm.Next(1, 20); 
  if(iRdm==i)
  {
  continue;
  }
}

int[] Source = new int[20];
            for (int i = 1; i <= 20; i++)
            {
                Source[i - 1] = i;
            }
            int[] Result = new int[10];
            for (int i = 1; i <= 10; i++)
            {
                Result[i - 1] = new Random().Next(Guid.NewGuid().GetHashCode());
            }

C# code:  
private static int[] GetRandom(int minValue, int maxValue, int count)
  {
  Random rnd = new Random();
  int length = maxValue - minValue + 1;
  byte[] keys = new byte[length];
  rnd.NextBytes(keys);
  int[] items = new int[length];
  for (int i = 0; i < length; i++)
  {
  items[i] = i + minValue;
  }
  Array.Sort(keys, items);
  int[] result = new int[count];
  Array.Copy(items, result, count);
  return result;
  }

public static void Main()
  {
  // Example Array
  int[] arr1 = GetRandom(1, 800, 50);
  }