Convert hexadecimal to integer

Question

I have this hexadecimal value "E365A931A000000".

I need to convert it to integer I’m using the following code.

string hex = "E365A931A000000";
CodLibercao = Convert.ToInt32(hex);

This code is sending me the following exception:

"Input string was not in a correct format."

What I’m doing wrong in conversion?

Answer 1

In fact the conversion from hexadecimal to integer requires the use of Parse, more specifically this format:

var codLiberacao = int.Parse(hex, System.Globalization.NumberStyles.HexNumber);

Only I did a test and this hexadecimal is too big for a 32-bit integer, then use long or Int64 for conversion:

var codLiberacao = Int64.Parse(hex, System.Globalization.NumberStyles.HexNumber);

Answer 2

Missed you using the conversion base. There is also a problem because this number does not fit in a int, you need to use a long (Convert.ToInt64()) to perform the conversion.

using static System.Console;
using static System.Convert;
using System.Numerics;
using System.Globalization;
                    
public class Program {
    public static void Main() {
        var hex = "E365A931A000000";
        WriteLine(ToInt64(hex, 16));
        hex = "E365A931";
        WriteLine(ToInt32(hex, 16));
        hex = "E365A931A000000000";
        WriteLine(BigInteger.Parse(hex, NumberStyles.HexNumber));
    }
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.

I showed an example with a smaller number to fit in a int. And a conversion that accommodates numbers of any size. One should evaluate whether it is worth using the BigInteger even.