|
There are at least two ways you can convert binary data (for example data from BinaryRead method) to a string.
1. Use VBS MultiByte functions :
Function SimpleBinaryToString(Binary)
'SimpleBinaryToString converts binary data (VT_UI1 | VT_ARRAY Or MultiByte string)
'to a string (BSTR) using MultiByte VBS functions
Dim I, S
For I = 1 To LenB(Binary)
S = S & Chr(AscB(MidB(Binary, I, 1)))
Next
SimpleBinaryToString = S
End Function
|
SimpleBinaryToString is clear function, but the function takes much time for large data. You can use it to convert data with up to 100kB of size (concatenation of large string takes much processor time). You can use similar function with better performance :
Function BinaryToString(Binary)
'Antonin Foller, http://www.motobit.com
'Optimized version of a simple BinaryToString algorithm.
Dim cl1, cl2, cl3, pl1, pl2, pl3
Dim L
cl1 = 1
cl2 = 1
cl3 = 1
L = LenB(Binary)
Do While cl1<=L
pl3 = pl3 & Chr(AscB(MidB(Binary,cl1,1)))
cl1 = cl1 + 1
cl3 = cl3 + 1
If cl3>300 Then
pl2 = pl2 & pl3
pl3 = ""
cl3 = 1
cl2 = cl2 + 1
If cl2>200 Then
pl1 = pl1 & pl2
pl2 = ""
cl2 = 1
End If
End If
Loop
BinaryToString = pl1 & pl2 & pl3
End Function
|
This function is up to 20 times faster than SimpleBinaryToString. You can use it to convert up to 2 MB of binary data.
2. Use ADODB.Recordset :
ADODB.Recordset lets you work with all supported VARIANT data types - also with binary and String data (VT_UI1 | VT_ARRAY, BSTR). It lets you convert between these two data formats :
Function RSBinaryToString(xBinary)
'Antonin Foller, http://www.motobit.com
'RSBinaryToString converts binary data (VT_UI1 | VT_ARRAY Or MultiByte string)
'to a string (BSTR) using ADO recordset
Dim Binary
'MultiByte data must be converted To VT_UI1 | VT_ARRAY first.
If vartype(xBinary)=8 Then Binary = MultiByteToBinary(xBinary) Else Binary = xBinary
Dim RS, LBinary
Const adLongVarChar = 201
Set RS = CreateObject("ADODB.Recordset")
LBinary = LenB(Binary)
If LBinary>0 Then
RS.Fields.Append "mBinary", adLongVarChar, LBinary
RS.Open
RS.AddNew
RS("mBinary").AppendChunk Binary
RS.Update
RSBinaryToString = RS("mBinary")
Else
RSBinaryToString = ""
End If
End Function
|
RSBinaryToString is not limitted by time - only by physical memory. The function is up to 100 times faster than MultiByte conversions - you can use it to convert up to 100MB data.
The function lets you also convert MultiByte strings to String. Next function converts MultiByte string to binary data :
Function MultiByteToBinary(MultiByte)
' 2000 Antonin Foller, http://www.motobit.com
' MultiByteToBinary converts multibyte string To real binary data (VT_UI1 | VT_ARRAY)
' Using recordset
Dim RS, LMultiByte, Binary
Const adLongVarBinary = 205
Set RS = CreateObject("ADODB.Recordset")
LMultiByte = LenB(MultiByte)
If LMultiByte>0 Then
RS.Fields.Append "mBinary", adLongVarBinary, LMultiByte
RS.Open
RS.AddNew
RS("mBinary").AppendChunk MultiByte & ChrB(0)
RS.Update
Binary = RS("mBinary").GetChunk(LMultiByte)
End If
MultiByteToBinary = Binary
End Function
|
3. Use ADODB.Stream :
ADODB.Stream lets you work with String and binary data type. It lets you also convert between these two data formats :
'Stream_BinaryToString Function
'2003 Antonin Foller, http://www.motobit.com
'Binary - VT_UI1 | VT_ARRAY data To convert To a string
'CharSet - charset of the source binary data - default is "us-ascii"
Function Stream_BinaryToString(Binary, CharSet)
Const adTypeText = 2
Const adTypeBinary = 1
'Create Stream object
Dim BinaryStream 'As New Stream
Set BinaryStream = CreateObject("ADODB.Stream")
'Specify stream type - we want To save text/string data.
BinaryStream.Type = adTypeBinary
'Open the stream And write text/string data To the object
BinaryStream.Open
BinaryStream.Write Binary
'Change stream type To binary
BinaryStream.Position = 0
BinaryStream.Type = adTypeText
'Specify charset For the source text (unicode) data.
If Len(CharSet) > 0 Then
BinaryStream.CharSet = CharSet
Else
BinaryStream.CharSet = "us-ascii"
End If
'Open the stream And get binary data from the object
Stream_BinaryToString = BinaryStream.ReadText
End Function
|
To save/retrieve binary data from a disk, binary file upload and download in ASP or better work with binary data (different code pages - ANSI, MAC, UTF, search binary data, etc.) see Pure and Huge ASP file upload with progress.. Copyright and use this code
The source code on this page and other samples at https://www.motobit.com/tips/
are a free code, you can use it as you want: copy it, modify it, use it in your products, ...
If you use this code, please:
1. Leave the author note in the source.
or
2. Link this sample from you page.
<A
Href="https://www.motobit.com/tips/detpg_binarytostring/"
Title="This article, demonstrates several versions of
source VBS code you can
use to work with binary
data in ASP and convert
the data to a String
format."
>Convert a binary data (BinaryRead) to a string by VBS</A>
|