Unicode string literals in VBA

问题:

I would like to declare (in a VBA class module) some private constant strings that contain Japanese characters. Is there a way to construct String literals (or combining literals in a way) that may be accepted as initializers in a Const declaration? i.e. something like:

Private Const MY_CONST = ...

or

Private Const MY_CONST As String = ...

I use MS Excel v14.0.6112.5000 (MS Office Professional Plus 2010).

What won't work:

• Pasting the Japanese chars directly in a string literal (e.g. ... = "変数") because the VBA editor will mess with the chars;
• Using ChrW() or ChrW$() (e.g. ... = ChrW$(22793) & ChrW$(25968)), because function calls are not allowed in Const initializers.

What I wouldn't like:

• Faking the Const by creating Private Property Get returning the string, because the string will be recreated every time I access the property (plus, is confusing and ugly... but, okay, the last two things are rather a matter of taste).

回答1:

Faking the Const by creating Private Property Get returning the string, because the string will be recreated every time I access the property (plus, is confusing and ugly... but, okay, the last two things are rather a matter of taste).

You need not recreate the string each time you access the property.

While this is still ugly as a matter of taste, make a read-only property (essentially Const, since it doesn't have a Property Let procedure), and construct the string in the Class_Initialize event:

'## CLASS MODULE
Private pUnicodeString As String

Sub Class_Initialize()
    pUnicodeString = ChrW(22793) & ChrW(25968)
End Sub

Property Get UnicodeString() As String
    UnicodeString = pUnicodeString
End Property

And then invoke it like:

'## STANDARD MODULE
Sub Test()
Dim c As myClass
Set c = New myClass

[A1].Value = c.UnicodeString

End Sub

回答2:

The encoding of VBA source file is Windows-1252, which does not support Japanese.

You cannot change the encoding of the source file, so you have to write its binary equivalent and then convert it before using it

Const str = vbTab & "Ype" ' I use vbTab because the VBA editor replaces tabulation with spaces
'...
ustr = StrConv(str, vbFromUnicode)
'ustr value is now "変数"

Use notepad to convert the string: copy-paste the unicode string, save the file as unicode (not utf-8) and open it as ANSI, then copy-paste it into the VBA editor without the first two characters (ÿþ), which is the BOM marker

Explanation

変数 is U+5909 U+6570 in unicode which is 0x09 0x59 0x70 0x65 in UTF-16LE (Windows unicode encoding), and this sequence corresponds to <tab>Ype in Windows-1252