Check this.
static void Main(string[] args)
{
double d1 = 3.49;
double d2 = 3.51;
Console.WriteLine(d1);
Console.WriteLine(d2);
int i1 = Convert.ToInt32(Math.Round(d1, 0, MidpointRounding.ToEven));
int i2 = Convert.ToInt32(Math.Round(d2, 0, MidpointRounding.ToEven));
Console.WriteLine(i1);
Console.WriteLine(i2);
Console.Read();
}