使用Visual Basic读取Unicode INI文件

Question

Reading INI values from a Unicode INI document with Visual Basic.

I thought that this was correct:

Private Class NativeMethods
    ' AJT 2014.11.28 Use the unicode function !!!
    <DllImport("kernel32", CharSet:=CharSet.Unicode)>
    Public Shared Function WritePrivateProfileString(section As String, key As String, val As String, filePath As String) As Boolean
    End Function

    ' AJT 2014.11.28 Use the unicode function !!!
    <DllImport("kernel32", CharSet:=CharSet.Unicode)>
    Public Shared Function GetPrivateProfileString(section As String, key As String, def As String, retVal As StringBuilder, size As Integer, filePath As String) As Integer
    End Function
End Class

But I am getting question marks when reading Russian data from the INI file.

Then I stumbled over this which defines:

 Private Declare Function GetPrivateProfileString _ Lib "kernel32" Alias "GetPrivateProfileStringA" _ (ByVal lpSectionName As String, _ ByVal lpKeyName As Any, _ ByVal lpDefault As String, _ ByVal lpbuffurnedString As String, _ ByVal nBuffSize As Long, _ ByVal lpFileName As String) As Long 

I noticed they used GetPrivateProfileStringA which makes me think I might need to use GetPrivateProfileStringW but now I am confused, as I am using:

<DllImport("kernel32", CharSet:=CharSet.Unicode)>

Please help.

Answer 1

The link you've provided predates .NET. What you're looking at (the Lib "kernel32" Alias "GetPrivateProfileStringA" syntax) is in fact the old way of importing unmanaged types and so on in VB6 , etc. This syntax will still work in VB.NET, but it is superseded by the DllImport functionality. If using this older way of doing things, you are correct in that you would need to specify "GetPrivateProfileStringW" rather than "GetPrivateProfileStringA" .

With regards to the problem you're experiencing, Russian characters may not be the actual cause of your problem; it may be that you are simply getting junk data back. This can happen if the parameters for your DllImport method are not defined using the correct types for one or more of the parameters.

Try taking a look at the following links. The PInvoke website usually contains useful information on how to correctly define the method signatures: https://www.pinvoke.net/default.aspx/kernel32.getprivateprofilestring https://www.pinvoke.net/default.aspx/kernel32.writeprivateprofilestring

For the sake of completeness, I've added these definitions below (copied directly from the links above, although I confess I have not tested them myself). If you are still having difficulty with this, it may be worth updating your answer with an example of the INI file content you are trying to read.

GetPrivateProfileString():

DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function GetPrivateProfileString(ByVal lpAppName As String, _
                        ByVal lpKeyName As String, _
                        ByVal lpDefault As String, _
                        ByVal lpReturnedString As StringBuilder, _
                        ByVal nSize As Integer, _
                        ByVal lpFileName As String) As Integer
End Function

WritePrivateProfileString():

<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function GetPrivateProfileString(ByVal lpAppName As String, _
                        ByVal lpKeyName As String, _
                        ByVal lpDefault As String, _
                        ByVal lpReturnedString As StringBuilder, _
                        ByVal nSize As Integer, _
                        ByVal lpFileName As String) As Integer
End Function