Writing file to folder with caron š in the name

[bobonwhidbey]

A user (with Windows 10) from Czech Republic has Aleš  as his account name. The first time he runs my app it fails when it tries to store a file in a new folder: C:\Users\Aleš\AppData\Roaming\MyAppName.  I obtain the folder name with

Code: Pascal  [Select][+][-]

1.  
2. Folder := GetSpecialFolder(CSIDL_APPDATA);
3.  
4. function GetSpecialFolder(const CSIDL: integer): string;
5. var
6.   RecPath: PChar;
7. begin
8.   RecPath := StrAlloc(MAX_PATH);
9.   try
10.     FillChar(RecPath^, MAX_PATH, 0);
11.     if SHGetSpecialFolderPath(0, RecPath, CSIDL, False) then
12.       Result := RecPath
13.     else
14.       Result := '';
15.   finally
16.     StrDispose(RecPath);
17.   end;
18. end;
19.  
20.  

where SHGetSpecialFolderPath is from the shlobj library.

I'm pretty sure the problem is because of the caron. What's the solution?

[lucamar]

A frequently recommended "fix" for those problems is to use the UnicodeString(/WideString) variants of the API calls (IIRC, SHGetSpecialFolderPathW in this case), to avoid the potential problems with automatic Windows codepage and UTF-8 conversions which might happen with ANSIString.

[bobonwhidbey]

With "regular" strings, I use:

Code: Pascal  [Select][+][-]

1. var
2. Folder : Pchar;
3.  
4.     Folder := StrAlloc(MAX_PATH);
5.     FillChar(Folder^, MAX_PATH, 0);
6.     SHGetSpecialFolderPath(0, Folder, CSIDL_APPDATA, False);    

When I tried to convert to wide strings, the compiler didn't like my StrAlloc line.

Code: Pascal  [Select][+][-]

1. var
2. Folder : Pwidechar;
3.  
4.     Folder := StrAlloc(MAX_PATH);
5.     FillChar(Folder^, MAX_PATH, 0);
6.     SHGetSpecialFolderPathW(0, Folder, CSIDL_APPDATA, False);    

How can I get the wide string folder name?

[balazsszekely]

Try this:

Code: Pascal  [Select][+][-]

1. uses shlobj;
2.  
3. function TForm1.GetSpecialFolder(const CSIDL: LongInt): string;
4. var
5.   Buffer: array[0..MaxPathLen] of WideChar;
6. begin
7.   Result := '';
8.   if SHGetFolderPathW(Handle, CSIDL, 0, SHGFP_TYPE_CURRENT, Buffer) = S_OK then
9.     Result := Buffer;
10. end;
11.  
12. procedure TForm1.Button1Click(Sender: TObject);
13. begin
14.   ShowMessage(GetSpecialFolder(CSIDL_APPDATA));
15. end;
16.  

[lucamar]

Barebones, something like:

Code: Pascal  [Select][+][-]

1. function GetAppData: WideString;
2. var
3.     Folder : WideString;
4. begin    
5.   SetLength(Folder, MAX_PATH+1);
6.   if SHGetSpecialFolderPath(0, PWideChar(Folder), CSIDL_APPDATA, False) then
7.     SetLength(Folder, StrLen(PChar(Folder)))
8.   Result := Folder;
9. end;

Note that you can also allocate space for the string with:

Code: Pascal  [Select][+][-]

1. APWideChar := WideStrAlloc(SomeLength);

so you could also do:

Code: Pascal  [Select][+][-]

1. var
2.     Folder : PWideChar;
3.  
4. [...etc ...]
5.  
6.   Folder := WideStrAlloc(MAX_PATH);
7.   SHGetSpecialFolderPath(0, Folder, CSIDL_APPDATA, False);

[bobonwhidbey]

Thanks Lucamar and GetMem, I've sent a test copy off to the user in Czech Republic to test. I'll report back when I can.

[Bart]

Unit Windirs has this function:

function GetWindowsSpecialDirUnicode(ID: Integer; CreateIfNotExists: Boolean = True): UnicodeString;

Bart

[bobonwhidbey]

It seems that many (most) dialogs don't accept Unicodestring variables, as opposed to string variables. For example, this:

Code: Pascal  [Select][+][-]

1. OpenDialog1.InitialDir := SomeUnicodeStringFolder:

results in a compiler warning. I have little familiarity with UnicodeStrings so I don't know what happens here. It would seem that the UnicodeString variable would be converted to string, and the wrong InitDir would appear. Is that right.

[JuhaManninen]

It seems that many (most) dialogs don't accept Unicodestring variables, as opposed to string variables.

Yes. Lazarus and LCL use "String" with UTF-8 encoding in the Unicode system. Please read this carefully:
 https://wiki.freepascal.org/Unicode_Support_in_Lazarus
You should also use the cross-platform code from libraries instead of calling WinAPI directly, when possible. It makes programming easier and your application becomes cross-platform automatically.

Try function GetUserDir from unit sysutils.