Converting Hex string to Int in C#

For a hex literal that’s not prefixed you can quite easily convert it using int.Parse in C#:

string hex = "142CBD";
// this returns 1322173
int intValue = int.Parse(hex, System.Globalization.NumberStyles.HexNumber);

But as you’ve probably noticed, most hex literals are prefixed with 0x (e.g. “0x142CBD”) which would throw a FormatException if you try to parse it using the above code.

In order to parse a 0x prefixed hex literal you need to use the Convert.ToInt32(string value, int fromBase) method instead:

string prefixedHex = "0x142CBD";
// this works, and returns 1322173
int intValue = Convert.ToInt32(prefixedHex , 16);