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Converting single precision float to a 4 byte string

Posted on 2003-03-01
Medium Priority
Last Modified: 2012-06-27
I need a function to convert a single precision floating point into a 4 byte string (so that I can story it into a binary file).

I have tried to do this by creating the function below

Public Declare Sub RtlMoveMemory Lib "kernel32" (ByVal hpvDest As Long, ByVal hpvSource As Long, ByVal cbCopy As Long)

Function floattostring(byval tFloat as single) as String
  dim sBuffer As String

  sBuffer = String(4, vbNullChar)
  RtlMoveMemory StrPtr(sBuffer), VarPtr(tFloat), 4
  floattostring = sBuffer
end function

however it doesn't seem to work (the string returned is always the 4 bytes "3F 3F 00 00").

Does anyone know a simple way I could convert this (either using memory copy/read api or actually converting it using an vb function)
Question by:dummstah

Accepted Solution

DocM earned 200 total points
ID: 8047597

 Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" ( _
  hpvDest As Any, hpvSource As Any, _
  ByVal cbCopy As Long)

Private Sub Single_To_4BytesString()

Dim str1 As String
Dim sng As Single

sng = 1.23456789

str1 = String(4, vbNullChar)
Call CopyMemory(ByVal str1, sng, 4)
For i = 1 To 4
 Debug.Print Asc(Mid(str1, i, 1)); " ";

End Sub

Author Comment

ID: 8047631
Works perfectly. Thanks a lot.

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