Test if a floating point number is an integer

Question

This code works (C# 3)

double d;
if(d == (double)(int)d) ...;

1. Is there a better way to do this?
2. For extraneous reasons I want to

Answer 1

Something like this

double d = 4.0;
int i = 4;

bool equal = d.CompareTo(i) == 0; // true