Use BigInteger.Parse
with a style of NumberStyles.HexNumber
:
using System;
using System.Globalization;
using System.Numerics;
class Program
{
static void Main()
{
var number = BigInteger.Parse("728faf34b64cd55c8d1d500268026ffb", NumberStyles.HexNumber);
Console.WriteLine(number);
}
}
Output:
152278043568215137367088803326132908027
solved Convert string BigInteger with base 16 in c#