8- or 10-character hex string to signed 32-bit Integer value - any better ways?

  • Thread starter Thread starter Joergen Bech
  • Start date Start date
J

Joergen Bech

Basically, I want to convert hex values in the range
"00000000" to "FFFFFFFF" to a signed, 32-bit Integer
value.

In VB6, I could just write lngValue = Val(hexstring$).

In VB.Net, I seem to be forced to do something like

---snip---
Private Function HexToInteger(ByVal hexValue As String) As Integer
If hexValue.ToLower.StartsWith("&h") Then
hexValue = hexValue.Substring(2)
End If
Dim value As Long = Long.Parse(hexValue,
Globalization.NumberStyles.HexNumber)
If value > Integer.MaxValue Then
value = value - 4294967296&
End If
Return CType(value, Integer)
End Function
---snip---

Have I overlooked a function in the framework?

Surely there is a faster/shorter/better way?

TIA,

Joergen Bech
 
Joergen said:
Basically, I want to convert hex values in the range
"00000000" to "FFFFFFFF" to a signed, 32-bit Integer
value.

In VB6, I could just write lngValue = Val(hexstring$).

In VB.Net, I seem to be forced to do something like

---snip---
Private Function HexToInteger(ByVal hexValue As String) As Integer
If hexValue.ToLower.StartsWith("&h") Then
hexValue = hexValue.Substring(2)
End If
Dim value As Long = Long.Parse(hexValue,
Globalization.NumberStyles.HexNumber)
If value > Integer.MaxValue Then
value = value - 4294967296&
End If
Return CType(value, Integer)
End Function
---snip---

Have I overlooked a function in the framework?

Surely there is a faster/shorter/better way?
Click to expand...

Well, you found Long.Parse but you missed Integer.Parse :(

Dim s1 As String = "1234"
Dim s2 As String = "FEDCBA98"

Dim i1 As Integer = Integer.Parse(s1, _
Globalization.NumberStyles.HexNumber)
Dim i2 As Integer = Integer.Parse(s2, _
Globalization.NumberStyles.HexNumber)
 
Joergen Bech @ post1.tele.dk> said:
Basically, I want to convert hex values in the range
"00000000" to "FFFFFFFF" to a signed, 32-bit Integer
value.
Click to expand...

return System.Convert.ToInt32(hexvalue, 16)


Armin
 
Well, you found Long.Parse but you missed Integer.Parse :(

Dim s1 As String = "1234"
Dim s2 As String = "FEDCBA98"

Dim i1 As Integer = Integer.Parse(s1, _
Globalization.NumberStyles.HexNumber)
Dim i2 As Integer = Integer.Parse(s2, _
Globalization.NumberStyles.HexNumber)
Click to expand...

Thanks. Knew I had overlooked something. Started off with
CInt, which does not handle 80000000-FFFFFFFF very well.

Because of that observation, along with this thread
http://www.dotnet247.com/247reference/msgs/58/293488.aspx
I was thrown off course and thought I had to make use of
the Long (64-bit) data type in my solution - never checking if
Integer.Parse(...HexNumber) worked correctly. Which it does.

Regards,

Joergen Bech
 
return System.Convert.ToInt32(hexvalue, 16)


Armin
Click to expand...

Excellent. Even better than Integer.Parse(...HexNumber).

Now, if only System.ParseNumbers was exposed so I could
skip the base check ...

But this is good enough for me.

Regards,

Joergen Bech
 
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