VB6实现MUI

一个VB6任务要求能在运行时,支持在不同语言间切换(英文,中文,日文,德文,法文和西班牙文);实质就是实现一个VB6的MUI程序.

Official Unicode support of VB6

这个需要的困难在于VB6显示文本的标准控件(Label,Textbox等)不支持Unicode;但字符串在其内部是按Unicode保存的,也就是说VB6本身是支持Unicode的.
VB6中,标准控件显示字符串的过程如下:

  • 标准控件先将Unicode字符串转换成ANSI字符串;
  • 标准控件尝试将ANSI字符串转换成其Font.Charset属性中指定的字符集格式的字符串;如果转换失败,则显示为问号(?).

具体可参照:Display Unicode Strings in Visual Basic 6.0.

Methods

因此,实现MUI程序的思路有两种:
1) 将标准控件替换为能支持Unicode的控件;
2) 将资源文件中不同字符集的文本,转换为ANSI格式,提供给标准控件使用;

第1)种方式可用 Forms 2.0 (fm20.dll);
第2)种方式,我在网上找到两篇文章,但各有不足:
a) Auto-Detect Language and Display Unicode in VB6 TextBox and Label Controls;
ChilkatCharset2控件需购买,具对日文的一些标点符号(如全角句号)不支持.
b) How To Convert from ANSI to Unicode & Unicode to ANSI for OLE
没有测试成功.

New Method

下面,着重介绍我自己认为比较成功的实现,它使用了ADODB.Stream(msado25.tlb);其实现思路如下:
1) 将程序中用到的文本保存为Unicode格式的资源文件中;
之所以将资源文本保存为双字节的Unicode格式,而非Utf8或Utf7格式,可省去从其它格式向VB6支持的Unicode格式转换过程.
2) 将显示文本的标准控件的Font.Charset,设置为程序要显示语言所对应的字符集,并设置一种支持这种字符集的字体到Font.Name属性;

If g_Str.NumJapanese > 0 Then
         charset = "Shift_JIS"
         Text1.Font.Name = "MS UI Gothic"
         Text1.Font.charset = 128

     ElseIf g_Str.NumKorean > 0 Then
         charset = "ks_c_5601-1987"
         Text1.Font.Name = "GulimChe"
         Text1.Font.charset = 129

     ElseIf g_Str.NumCentralEuro > 0 Then
         charset = "windows-1250"
         Text1.Font.Name = "Arial"
         Text1.Font.charset = 238

     ElseIf g_Str.NumArabic > 0 Then
         charset = "windows-1256"
         Text1.Font.Name = "Traditional Arabic"
         Text1.Font.charset = 178

     ElseIf g_Str.NumHebrew > 0 Then
         charset = "windows-1255"
         Text1.Font.Name = "David"
         Text1.Font.charset = 177

     ElseIf g_Str.NumCyrillic > 0 Then
         charset = "windows-1251"
         Text1.Font.Name = "Arial"
         Text1.Font.charset = 204

     ElseIf g_Str.NumGreek > 0 Then
         charset = "windows-1253"
         Text1.Font.Name = "Arial"
         Text1.Font.charset = 161

     ElseIf g_Str.NumThai > 0 Then
         charset = "windows-874"
         Text1.Font.Name = "Angsana New"
         Text1.Font.charset = 222

     ElseIf g_Str.NumChinese > 0 Then
         charset = "gb2312"
         Text1.Font.Name = "SimSun"
         Text1.Font.charset = 134
         ' An alternative is to use Big5:
         ' Text1.Font.Name = "MingLiu"
         'charset = "big5"
         'fontCh = 136

     Else
         charset = "windows-1252"
         Text1.Font.charset = 0
         Text1.Font.Name = "Arial"
     End If

3) 根据要显示的语言,利用ADODB.Stream将资源文件中Unicode格式保存的字符串转换成操作系统的区域语言(Locale)支持字符集的字符串;

 ' 调用API来获取操作系统默认的区域语言设置(LocaleID)
 Private Declare Function GetSystemDefaultLCID Lib "kernel32" () As Long

 ' 将Unicode字符串,转换为指定字符集的字节数组;
 ' 用于转换用资源文件中读取的文本;
 Public Function ConvertStringToBytes(ByRef strText As String, charset As String) As Byte()

     Dim objStream As ADODB.Stream
     Dim data() As Byte

     ' init stream
     Set objStream = New ADODB.Stream
     objStream.charset = charset
     objStream.Mode = adModeReadWrite
     objStream.Type = adTypeText
     objStream.Open

     ' write bytes into stream
     objStream.WriteText strText
     objStream.Flush

     ' rewind stream and read text
     objStream.Position = 0
     objStream.Type = adTypeBinary
 '    objStream.Read 3 ' skip first 3 bytes as this is the utf-8 marker
     data = objStream.Read()

     ' close up and return
     objStream.Close
     ConvertStringToUtf8Bytes = data

 End Function
 ' 转换为指定字符集的字节数组,转换为ANSI(即LocaleID)对应的字符集的字符串;
 ' 用于将ConvertStringToBytes()返回的字节数组转换为GetCharset()字符集的字符串.
 Public Function ConvertBytesToString(ByRef data() As Byte, charset As String) As String

     Dim objStream As ADODB.Stream
     Dim strTmp As String

     ' init stream
     Set objStream = New ADODB.Stream
     objStream.charset = charset
     objStream.Mode = adModeReadWrite
     objStream.Type = adTypeBinary
     objStream.Open

     ' write bytes into stream
     objStream.Write data
     objStream.Flush

     ' rewind stream and read text
     objStream.Position = 0
     objStream.Type = adTypeText
     strTmp = objStream.ReadText

     ' close up and return
     objStream.Close
     ConvertUtf8BytesToString = strTmp

 End Function

 '获取操作系统默认区域语言对应的字符集
 Public Function GetCharset() As String
     Dim localeId As Long
     Dim charset As String

     ' 获取操作系统的LocaleId
     localeId = GetSystemDefaultLCID()

     Select Case localeId

         Case 1033
             charset = "windows-1252"
         Case 2052
             charset = "gb2312"
         Case 1041
             charset = "Shift_JIS"
         Case Else
             charset = "windows-1252"
     End Select

     GetCharset = charset
 End Function

 '显示资源文本中的文本
 Private Sub DisplayText(filename As String)

     '保存资源文本中的文本的变量
     Dim textBytes As Variant
     Dim f As New FileSystemObject
     Dim fs As TextStream
     '将Unicode文本读取到变量中
     Set fs = f.OpenTextFile(filename, ForReading, False, TristateTrue)

     Do While Not fs.AtEndOfStream
         textBytes = fs.ReadAll
     Loop

     fs.Close

     ' Convert to a Unicode string:
     Dim s As String
     s = textBytes
     Dim t As Long
     ' CkString是免费的第三方组件,可自动判定一个字符串所对应的字符集
     ' 下载地址:http://www.chilkatsoft.com/download/CkString.zip
     Dim g_Str As New CkString
      g_Str.Str = s

     '获取资源文本所代表的字符集名称,设置对应的字体和字符集到textbox上
     Dim charset As String
     If g_Str.NumJapanese > 0 Then  '日文
         charset = "Shift_JIS"
         Text1.Font.Name = "MS UI Gothic"
         Text1.Font.charset = 128

     ElseIf g_Str.NumKorean > 0 Then '韩语
         charset = "ks_c_5601-1987"
         Text1.Font.Name = "GulimChe"
         Text1.Font.charset = 129

     ElseIf g_Str.NumCentralEuro > 0 Then '中欧语言
         charset = "windows-1250"
         Text1.Font.Name = "Arial"
         Text1.Font.charset = 238

     ElseIf g_Str.NumArabic > 0 Then '阿拉伯语
         charset = "windows-1256"
         Text1.Font.Name = "Traditional Arabic"
         Text1.Font.charset = 178
     ElseIf g_Str.NumGreek > 0 Then  '希腊语
         charset = "windows-1253"
         Text1.Font.Name = "Arial"
         Text1.Font.charset = 161
     ElseIf g_Str.NumThai > 0 Then  '泰语
         charset = "windows-874"
         Text1.Font.Name = "Angsana New"
         Text1.Font.charset = 222
     ElseIf g_Str.NumChinese > 0 Then '中文
         charset = "gb2312"
         Text1.Font.Name = "SimSun"
         Text1.Font.charset = 134
         ' 繁体则使用Big5:
         ' Text1.Font.Name = "MingLiu"
         'charset = "big5"
         'Text1.Font.charset = 136
     Else '默认值
         charset = "windows-1252"
         Text1.Font.charset = 0
         Text1.Font.Name = "Arial"
     End If

     Dim bytes() As Byte
     Dim g_OSCharset As String
     '获取操作系统默认语言对应的字符集
     g_OSCharset = GetCharset()
     '先将Unicode资源文本转换成对应的字节数组;
     bytes = ConvertStringToBytes(s, charset)
     '将字节数组转换成ANSI(即默认字符集)对应的字符串
     vbstr2 = ConvertBytesToString(bytes, g_OSCharset)
     ' 设置字符串到VB6的标准控件中
     Me.Text1.Text = vbstr2
 End Sub

参考:

1) 字符集列表及LocaleId列表(http://www.livio.net/main/charset.asp)

http://www.cnblogs.com/beiguren/archive/2010/03/08/1680713.html