VB.NET

Convert utf-8 Text File to Windows-1252

Demonstrates how to convert a text file using the utf-8 byte representation to windows-1252. VB.NET

Dim success As Boolean = False

' Converts a file containing the following to windows-1252:

' <greetings>
'     <message>Hello, world!</message>
'     <message>¡Hola, mundo!</message>
'     <message>Bonjour, le monde!</message>
'     <message>Hallo, Welt!</message>
'     <message>Olá, mundo!</message>
'     <message>Привет, мир!</message>
'     <message>你好，世界！</message>
'     <message>こんにちは、世界！</message>
'     <message>안녕하세요, 세계!</message>
'     <message>😊🌍</message>
' </greetings>

' --------------------------------------------------------------------------------------------------------------------------
' Note:
' Windows-1252 is an 8-bit single-byte encoding. It can only encode:
' 
'     The basic ASCII set (0x00–0x7F).
'     Latin-1 Supplement (0xA0–0xFF), plus some extra printable characters (like curly quotes, €, etc.).
'     In total: 256 possible code points, covering most Western European languages but nothing outside of Latin script.

' --------------------------------------------------------------------------------------------------------------------------
' Characters in your XML that are representable
' 
'     Hello, world! ✅ (ASCII only)
'     ¡Hola, mundo! ✅ (inverted exclamation mark U+00A1 is in Windows-1252)
'     Bonjour, le monde! ✅
'     Hallo, Welt! ✅
'     Olá, mundo! ✅ (U+00E1 á and U+00F3 ó are in Windows-1252)

' --------------------------------------------------------------------------------------------------------------------------
' Characters that break conversion
' 
'     Russian / Cyrillic: Привет, мир!
'     → These are Cyrillic characters (U+041F … U+0440). Not representable in Windows-1252. Conversion would require replacement (e.g. with ? or XML character references).
'     Chinese: 你好，世界！
'     → CJK ideographs (U+4F60, U+597D, etc.). Not in Windows-1252.
'     Japanese: こんにちは、世界！
'     → Hiragana + CJK. Not in Windows-1252.
'     Korean: 안녕하세요, 세계!
'     → Hangul syllables. Not in Windows-1252.
'     Emoji: 😊🌍
'     → Unicode Supplementary Multilingual Plane (U+1F60A, U+1F30D). Windows-1252 cannot encode any emoji.

Dim bd As New Chilkat.BinData

' Load the utf-8 bytes.
success = bd.LoadFile("qa_data/xml/utf8test.xml")
If (success = False) Then
    Debug.WriteLine(bd.LastErrorText)
    Exit Sub
End If


' If allOrNone = True, then the conversion fails and the contents of the BinData
' are left unchanged if any char is unconvertable.

' If allOrNone = False, then non-convertable chars are discarded.
Dim allOrNone As Boolean = False
Dim fromCharset As String = "utf-8"
Dim toCharset As String = "windows-1252"
success = bd.CharsetConvert(fromCharset,toCharset,allOrNone)

' The return value will be False if any utf-8 chars were discarded because of non-convertability.
If (success = False) Then
    Debug.WriteLine("Some utf-8 chars could not be converted to windows-1252")
Else
    Debug.WriteLine("All utf-8 chars were converted to windows-1252")
End If


success = bd.WriteFile("c:/temp/qa_output/out.xml")

' The output file contains the following, where all non-convertable chars were discarded

' <greetings>
'     <message>Hello, world!</message>
'     <message>¡Hola, mundo!</message>
'     <message>Bonjour, le monde!</message>
'     <message>Hallo, Welt!</message>
'     <message>Olá, mundo!</message>
'     <message>, !</message>
'     <message></message>
'     <message></message>
'     <message>, !</message>
'     <message></message>
' </greetings>