Convert decimals to Hex

Question

I want to convert decimals into Hex:

string hex = IntToString(dezimal,
             new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                          'A', 'B', 'C', 'D', 'E', 'F'});
textBoxHexa.Text = hex;

But I get an error:

Input string was not in a correct format

Is this even the best way to do it? If not, what better ways are there?

Possible duplicate of [int to hex string](https://stackoverflow.com/questions/4690480/int-to-hex-string) — PaulF, Feb 26 '18 at 17:22
There is no need to convert. Decimals are stored as numbers in binary. You just need to change display method is you need a hex output. — jdweng, Feb 26 '18 at 17:24
you have to show the code thats failing. ie IntToString. Turn on 'break on exception thrown' in the Debug->Exception settings to see which line is failing — pm100, Feb 26 '18 at 17:27
As the error message seems to bear no relation to the code shown - are you taking a user input string & then trying to parse that to an integer first. You would get "Input string was not in a correct format" exception if the user typed an invalid integer string (maybe a decimal) & you tried parsing with the Int32.Parse() method. — PaulF, Feb 26 '18 at 17:53

score -1 · Answer 1 · answered Feb 26 '18 at 17:44

-1

Decimals can't be represented directly by hexadecimal, there's no floating point, for that you need a representation of the floating point number, the most common is the IEEE-754 representation which uses the actual processors.

In case you want that representation you can do this (using unsafe):

decimal m = 3.4353M;
byte* data = (byte*)&m;

string hex = "";

for(int buc = 0; buc < 16; buc++)
    hex += data[buc].ToString("X2");

//Result: 00000400000000003186000000000000

answered Feb 26 '18 at 17:44

Gusman

14,905
2
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Look into `BitConverter.GetBytes()` [MSDN](https://msdn.microsoft.com/en-us/library/yhwsaf3w(v=vs.110).aspx). It provides a managed way to get a byte representation of a value as a byte array, without the pointer arithmetic. – Trevor Feb 26 '18 at 18:10
@Trevor Look at it by yourself, there's no conversion from decimal (decimal is not the same as float). – Gusman Feb 26 '18 at 18:25
True, `GetBytes()` does not have an overload for .NET's `decimal` data type. But NET's [`decimal`](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/decimal) data type is not an [IEEE-754](https://en.wikipedia.org/wiki/IEEE_754) defined type like you suggest. The overload is likely missing because the internal representation of a framework-specific type would be of limited use. To be honest, it's all moot until the OP provides more information. – Trevor Feb 26 '18 at 19:07

whatthefish · Answer 2 · 2018-02-26T18:07:10.433

-3

First of all IntToString converts an integer to string, not from decimal to hex.

Check here for IntToString use

TO convert from decimal to hex use the method: ToString("X")

// Store integer 50
int decValue = 50;

// Convert integer 182 as a hex in a string variable
string hexValue = decValue.ToString("X");

Or you could use the following method as well:

string.format("{0:x}", decValue);

Refer to this answer for more details

edited Feb 26 '18 at 18:07

answered Feb 26 '18 at 17:27

whatthefish

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17

You need to be more precise in your wording - you seem to imply that you can convert from "decimal" type to a hex string with _ToString("X")_. You will find this throws a FormatException. You can only use that formatting for integral types (short, int, long, ushort etc). – PaulF Feb 26 '18 at 17:40
1

How do you know what IntToString does? We do not know the type of `dezimal` , it could be anyting – pm100 Feb 26 '18 at 18:04
Stop posting random answers and test it by yourself. It fails miserably also. – Gusman Feb 26 '18 at 18:28
for all we know dezimal is a string – pm100 Feb 26 '18 at 19:05
@pm100 It cannot be string since the first argument for `IntToString` is an int argument. – whatthefish Feb 26 '18 at 23:37
@Ramesh how do you know what the first argument is? OP has not provided the definition for that function. You’re literally guessing. This question is unanswerable until the OP provides a [MCVE] – maccettura Feb 27 '18 at 00:02
@maccettura I am not guessing it but that is what is mentioned in the arguments of the function. Here is the definition of the `IntToString` function: `int IntToString(int num, char[] str, int maxlength)` – whatthefish Feb 27 '18 at 00:15
@Ramesh you’ve linked a random c++ library that includes an IntToString function. How on earth is that helpful or relevant? – maccettura Feb 27 '18 at 00:19

Convert decimals to Hex

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