How to convert numbers between hexadecimal and decimal

Question

How do you convert between hexadecimal numbers and decimal numbers in C#?

Answer 1

If it's a really big hex string beyond the capacity of the normal integer:

For .NET 3.5, we can use BouncyCastle's BigInteger class:

String hex = "68c7b05d0000000002f8";
// results in "494809724602834812404472"
String decimal = new Org.BouncyCastle.Math.BigInteger(hex, 16).ToString();

.NET 4.0 has the BigInteger class.