How to create a Random Unique number in C# using a Recursive Method?

I'm trying to generate 5 random numbers between 1-10 which do not have duplicate values. Therefore, I've created a recursive method which should check to see if the value created for whichever position in the array has been used already. If it has, then it will create a new random number and check again.

Here's my code:

    static Random randomObject = new Random();

    static void Main(string[] args)
    {

    long[] randomArr = new long[5];


    for (int i = 0; i < randomArr.Length; i++ )
    {
        if (randomArr[i] == randomArr[0])
        {
            randomArr[i] = randomObject.Next(1, 11);
        }
        else 
        {
            long check = randomObject.Next(1, 11);
            randomArr[i] = CheckIfUnique(check, randomArr);
        }
    }

    Console.WriteLine("\nPress the [enter] key to continue...");
    Console.ReadLine();

}

static long CheckIfUnique(long a, long[] b) 
{
    for (int i = 0; i <= b.GetUpperBound(0); i++) 
    {
        if (a == b[i])
        {
           a = randomObject.Next(1, 11);
           CheckIfUnique(a, b);
        }
    }
    return a;
}

But I'm still getting duplicate values. Does anyone know if there is an error in my logic, or if the compiler will crap out after so many recursive steps?