Visual Basic Programming Code Examples

Visual Basic > Strings Code Examples

Convert Hex string to Long



Convert Hex string to Long

converts a hexadecimal string into a long
Returns zero if error occurs


Public Function ConvertHexToLong(sHex As String) As Long

On Error GoTo errHandler:
    Dim n As Integer
    Dim sTemp As String * 1
    Dim nTemp As Integer
    Dim nFinal() As Integer
    Dim bNegative As Boolean
    ReDim nFinal(0)
    If LenB(sHex) = 0 Then
        ConvertHexToLong = 0
        Exit Function
    End If
    bNegative = False
    For n = Len(sHex) To 1 Step -1
        sTemp = Mid$(sHex, n, 1)
        nTemp = Val(sTemp)
        If nTemp = 0 Then
            Select Case UCase(sTemp)
                Case "A"
                    nTemp = 10
                Case "B"
                    nTemp = 11
                Case "C"
                    nTemp = 12
                Case "D"
                    nTemp = 13
                Case "E"
                    nTemp = 14
                Case "F"
                    nTemp = 15
                Case "-"
                    bNegative = True
                Case Else
                    nTemp = 0
            End Select
        End If
        ReDim Preserve nFinal(UBound(nFinal) + 1)
        nFinal(UBound(nFinal)) = nTemp
    Next
    ConvertHexToLong = nFinal(1)
    For n = 2 To UBound(nFinal)
        ConvertHexToLong = ConvertHexToLong + (nFinal(n) * (4 ^ (n * 2 - 2)))
    Next
    If bNegative Then ConvertHexToLong = ConvertHexToLong - (ConvertHexToLong * 2)
Exit Function
errHandler:

ConvertHexToLong = 0

End Function