C#/Unity3D – Shuffling an Arrayvia http://mrmoss.net/2013/cunity3d-shuffling-an-array/

shuffle.cs

 public void Shuffle<T>(T[] obj)
{
    for (var i = 0; i < obj.Length; i++)
    {
        var temp = obj[i];
        var obj_index = Random.Range(0, obj.Length);
        obj[i] = obj[obj_index];
        obj[obj_index] = temp;
    }
}