Any way to convert from Double to Hex in vb? - vb.net

Question

I want to add a text box where a user can input a number. No matter how large or small the number, it needs to be stored as a double. Then with a click button, the hex equivalent will be displayed in a second text box. Bonus points if you can show me how to take the 16 byte hex and change it to 4 variables with 4 bytes each.
For example, user enters 1234.56 in textbox1. Clicks button 1, and textbox2 displays the hex equivilent "40934A3D70A3D70A" Then take that string, and extract to 4 different 4-byte strings so str1=1093, str2=4A3D, str3=70a3, str4=d70A.

Answer 1

Are you looking for BitConverter? C# implementation:
double source = 1234.56;
// 40934A3D70A3D70A
string result = string.Concat(BitConverter
.GetBytes(source)
.Reverse()
.Select(b => b.ToString("X2")));
Having got result, extract its parts with Substring:
string str1 = result.Substring(0, 4);
string str2 = result.Substring(4, 4);
string str3 = result.Substring(8, 4);
string str4 = result.Substring(12, 4);

Answer 2

If you are looking for a C# implementation, try this:
static void Main(string[] args)
{
var number = 1234.56;
string hex = DoubleToHex(number);
string part1 = hex.Substring(0, 4);
string part2 = hex.Substring(4, 4);
string part3 = hex.Substring(8, 4);
string part4 = hex.Substring(12, 4);
}
internal static string DoubleToHex(double value)
{
var b = BitConverter.GetBytes(value).Reverse();
string result = string.Join(string.Empty, b.Select(i => i.ToString("X2")).ToArray());
return result;
}

Answer 3

This is the most efficient answer you're going to get:
unsafe static void Main()
{
var value = 1234.56;
var pLong = (long*)&value;
var fullString = (*pLong).ToString("X");
var pShort = (short*)pLong;
short value0 = *pShort, value1 = *(pShort + 1), value2 = *(pShort + 2),
value3 = *(pShort + 3);
string s0 = value0.ToString("X"), s1 = value1.ToString("X"), s2 = value2.ToString("X"),
s3 = value3.ToString("X");
Debug.Print(fullString);
Debug.Print(s0);
Debug.Print(s1);
Debug.Print(s2);
Debug.Print(s3);
}
Output:
40934A3D70A3D70A
D70A
70A3
4A3D
4093

Answer 4

Translation of Dmitry Bychenko answer to VB.NET:
Imports SplitValue = System.Tuple(Of String, String, String, String)
Module Module1
Function DoubleToByteArray(ByVal AValue As Double) As Byte()
Return BitConverter.GetBytes(AValue).Reverse().ToArray()
End Function
Function SplitByteArray(ByRef AValue As Byte()) As SplitValue
Dim StringValue As String = String.Join("", From AByte In AValue Select AByte.ToString("X2"))
Return New SplitValue(StringValue.Substring(0, 4), StringValue.Substring(4, 4), StringValue.Substring(8, 4), StringValue.Substring(12, 4))
End Function
Sub Main()
Dim Result As SplitValue
Result = SplitByteArray(DoubleToByteArray(1234.56))
Console.WriteLine(Result)
Console.ReadLine()
End Sub
End Module
Output:
(4093, 4A3D, 70A3, D70A)

Answer 5

try it: DoubleToHex
//dashseparator 0 /2/4
public string DoubleToHex(double d, bool reverse = false, int dashSeparator = 0)
{
byte[] bytes = BitConverter.GetBytes(d);
if (reverse) bytes = bytes.Reverse().ToArray();
var hex = BitConverter.ToString(bytes);
var hex4 = "";
if (dashSeparator == 2) return hex;
if (dashSeparator == 4)
{
hex = hex.Replace("-", "");
hex = Regex.Replace(hex, ".{4}", "$0-").TrimEnd('-');
return hex;
}
return hex.Replace("-", "");
}
sample Output:
Double: 1234.56
Hex: 0AD7A3703D4A9340
Hex in Reverse order: 40934A3D70A3D70A
Hex in Reverse order separate by 2 digits: 40-93-4A-3D-70-A3-D7-0A
Hex in Reverse order separate by 4 digits: 4093-4A3D-70A3-D70A
you can :
-control the generated Hex to be displayed in order/ reverse order.
-Add dash separator by 0 (no separator) / 2 /4 digits
Edit:
Vb.Net Version
Converting Code to Vb.Net
'dashseparator 0 /2/4
Public Function DoubleToHex(d As Double, Optional reverse As Boolean = False, Optional dashseparator As Integer = 0) As String
Dim bytes As Byte() = BitConverter.GetBytes(d)
If reverse Then
Array.Reverse(bytes)
End If
Dim hex = BitConverter.ToString(bytes)
Dim hex4 = ""
If dashseparator = 2 Then
Return hex
End If
If dashseparator = 4 Then
hex = hex.Replace("-", "")
hex = Regex.Replace(hex, ".{4}", "$0-").TrimEnd("-"C)
Return hex
End If
Return hex.Replace("-", "")
End Function