Question

如何将UTF-8编码的字符串写入vba的文本文件，如

Dim fnum As Integer
fnum = FreeFile
Open "myfile.txt" For Output As fnum
Print #fnum, "special characters: äöüß" 'latin-1 or something by default
Close fnum

应用程序级别是否有一些设置？

Answer 1

我在web上找到答案：

Dim fsT As Object
Set fsT = CreateObject("ADODB.Stream")
fsT.Type = 2 'Specify stream type - we want To save text/string data.
fsT.Charset = "utf-8" 'Specify charset For the source text data.
fsT.Open 'Open the stream And write binary data To the object
fsT.WriteText "special characters: äöüß"
fsT.SaveToFile sFileName, 2 'Save binary data To disk

当然不像我预期的那样......

Answer 2

您可以使用CreateTextFile或OpenTextFile方法，两者都具有对编码设置有用的属性“unicode”。

object.CreateTextFile(filename[, overwrite[, unicode]])        
object.OpenTextFile(filename[, iomode[, create[, format]]])

示例：覆盖：

CreateTextFile:
 fileName = "filename"
 Set fso = CreateObject("Scripting.FileSystemObject")
 Set out = fso.CreateTextFile(fileName, True, True)
 out.WriteLine ("Hello world!")
 ...
 out.close

示例：附加：

 OpenTextFile Set fso = CreateObject("Scripting.FileSystemObject")
 Set out = fso.OpenTextFile("filename", ForAppending, True, 1)
 out.Write "Hello world!"
 ...
 out.Close

详情请见MSDN docs

Answer 3

这会在文件的开头写一个字节顺序标记，这在UTF-8文件中是不必要的，而某些应用程序（在我的情况下，SAP）不喜欢它。解决方案：Can I export excel data with UTF-8 without BOM?

Answer 4

这是另一种方法 - 使用API函数WideCharToMultiByte：

Option Explicit

Private Declare Function WideCharToMultiByte Lib "kernel32.dll" ( _
  ByVal CodePage As Long, _
  ByVal dwFlags As Long, _
  ByVal lpWideCharStr As Long, _
  ByVal cchWideChar As Long, _
  ByVal lpMultiByteStr As Long, _
  ByVal cbMultiByte As Long, _
  ByVal lpDefaultChar As Long, _
  ByVal lpUsedDefaultChar As Long) As Long

Private Sub getUtf8(ByRef s As String, ByRef b() As Byte)
Const CP_UTF8 As Long = 65001
Dim len_s As Long
Dim ptr_s As Long
Dim size As Long
  Erase b
  len_s = Len(s)
  If len_s = 0 Then _
    Err.Raise 30030, , "Len(WideChars) = 0"
  ptr_s = StrPtr(s)
  size = WideCharToMultiByte(CP_UTF8, 0, ptr_s, len_s, 0, 0, 0, 0)
  If size = 0 Then _
    Err.Raise 30030, , "WideCharToMultiByte() = 0"
  ReDim b(0 To size - 1)
  If WideCharToMultiByte(CP_UTF8, 0, ptr_s, len_s, VarPtr(b(0)), size, 0, 0) = 0 Then _
    Err.Raise 30030, , "WideCharToMultiByte(" & Format$(size) & ") = 0"
End Sub

Public Sub writeUtf()
Dim file As Integer
Dim s As String
Dim b() As Byte
  s = "äöüßµ@€|~{}[]²³\ .." & _
    " OMEGA" & ChrW$(937) & ", SIGMA" & ChrW$(931) & _
    ", alpha" & ChrW$(945) & ", beta" & ChrW$(946) & ", pi" & ChrW$(960) & vbCrLf
  file = FreeFile
  Open "C:\Temp\TestUtf8.txt" For Binary Access Write Lock Read Write As #file
  getUtf8 s, b
  Put #file, , b
  Close #file
End Sub

Answer 5

我调查了Máťa的答案，他的名字暗示着编码资格和经验。 VBA docs说CreateTextFile(filename, [overwrite [, unicode]])创建一个文件“作为Unicode或ASCII文件。如果文件创建为Unicode文件，则值为True;如果创建为ASCII文件，则为False。如果省略，则为假设是ASCII文件。“一个文件存储unicode字符，但编码是什么？未编码的unicode无法在文件中表示。

OpenTextFile(filename[, iomode[, create[, format]]])的{{3}}为格式提供了第三种选择：

TriStateDefault 2“使用系统默认值打开文件。”
TriStateTrue 1“将文件作为Unicode打开。”
TriStateFalse 0“以ASCII格式打开文件。”

Máťa为这个论点传递-1。

从VBA doc page判断（不是VBA，但我认为反映了基础Windows操作系统如何表示unicode字符串并回应MS Office的现实，我不知道）系统默认是使用1字节/ unicode的编码使用区域设置的ANSI代码页的字符。 UnicodeEncoding是UTF-16。文档还描述了UTF-8也是一种“Unicode编码”，这对我来说很有意义。但我还不知道如何为VBA输出指定UTF-8，也不知道我用OpenTextFile（,,, 1）写入磁盘的数据是UTF-16编码的。 VB.NET documentation很有帮助。

Answer 6

将字符串转换为UTF-8字符串的传统方法如下：

StrConv("hello world",vbFromUnicode)

所以简单地说：

Dim fnum As Integer
fnum = FreeFile
Open "myfile.txt" For Output As fnum
Print #fnum, StrConv("special characters: äöüß", vbFromUnicode)
Close fnum

不需要特殊的COM对象

保存使用VBA编码的UTF-8文本文件

6 个答案: