win32utils devel - Feb 2004 - Wide strings and LPCTSTR types

All,

I was experimenting with converting LPCTSTR strings to wide strings with
something like this:

// Converts a Ruby string to a LPWSTR
LPCTSTR AllocWideLString(VALUE rbString){
   char* str = STR2CSTR(rbString);
   int length = (strlen(str)+1) * sizeof(WCHAR);
   LPCTSTR lpStr = (LPCTSTR)malloc(length);
   
   MultiByteToWideChar(
	CP_ACP,
      0,
      str,
      strlen(str)+1,
      (LPWSTR)lpStr,
      length
   );
   
   return lpStr;
}

But, that didn''t seem to work very well in testing.  Is there a better
way?  Otherwise, I''ll have to stick to casting for now.

Also, I noticed that there''s a IsTextUnicode() function.  Should I be
employing that somehow?

Dan

Hi,
> 
> All,
> 
> I was experimenting with converting LPCTSTR strings to wide strings with
> something like this:
> 
> // Converts a Ruby string to a LPWSTR
> LPCTSTR AllocWideLString(VALUE rbString){
>    char* str = STR2CSTR(rbString);
>    int length = (strlen(str)+1) * sizeof(WCHAR);
>    LPCTSTR lpStr = (LPCTSTR)malloc(length);
>    
>    MultiByteToWideChar(
> 	CP_ACP,
>       0,
>       str,
>       strlen(str)+1,
>       (LPWSTR)lpStr,
>       length
>    );
>    
>    return lpStr;
> }
> 
> But, that didn''t seem to work very well in testing.  Is there a
better
> way?  Otherwise, I''ll have to stick to casting for now.
> 
> Also, I noticed that there''s a IsTextUnicode() function.  Should I
be
> employing that somehow?
Do You still have trouble with MultiByteToWideChar?

Maybe MultiByteToWideChar hates you :)

Would you try mbstowcs like following?

    nLen = strlen(szText) + 1;
    wszBuffer = malloc(nLen) * sizeof(WCHAR);
    mbstowcs(wszBuffer, szText, nLen);


Regards,

Park Heesob



--MIME Multi-part separator--

> -----Original Message-----
> From: win32utils-devel-bounces@rubyforge.org 
> [mailto:win32utils-devel-bounces@rubyforge.org] On Behalf Of 
> win32utils-devel@rubyforge.org
> Sent: Wednesday, February 25, 2004 5:07 PM
> To: win32utils-devel@rubyforge.org
> Subject: Re:[Win32utils-devel] Wide strings and LPCTSTR types
<snip>
> Would you try mbstowcs like following?
> 
>     nLen = strlen(szText) + 1;
>     wszBuffer = malloc(nLen) * sizeof(WCHAR);
>     mbstowcs(wszBuffer, szText, nLen);
I tried this:

LPCTSTR AllocWideLPCString(VALUE rbString){
   char* szText = STR2CSTR(rbString);
   int nLen = (strlen(szText) + 1) * sizeof(LPCTSTR);
   LPCTSTR wszBuffer = (LPCTSTR)malloc(nLen);
   mbstowcs(wszBuffer, szText, nLen);
   return wszBuffer;
}

It still didn''t work.

Dan

> 
> > -----Original Message-----
> > From: win32utils-devel-bounces@rubyforge.org 
> > [mailto:win32utils-devel-bounces@rubyforge.org] On Behalf Of 
> > win32utils-devel@rubyforge.org
> > Sent: Wednesday, February 25, 2004 5:07 PM
> > To: win32utils-devel@rubyforge.org
> > Subject: Re:[Win32utils-devel] Wide strings and LPCTSTR types
> <snip>
> > Would you try mbstowcs like following?
> > 
> >     nLen = strlen(szText) + 1;
> >     wszBuffer = malloc(nLen) * sizeof(WCHAR);
> >     mbstowcs(wszBuffer, szText, nLen);
> 
> I tried this:
> 
> LPCTSTR AllocWideLPCString(VALUE rbString){
>    char* szText = STR2CSTR(rbString);
>    int nLen = (strlen(szText) + 1) * sizeof(LPCTSTR);
should be
     int nLen = (strlen(szText) + 1) * sizeof(WCHAR);
>    LPCTSTR wszBuffer = (LPCTSTR)malloc(nLen);
>    mbstowcs(wszBuffer, szText, nLen);
>    return wszBuffer;
> }
> 
> It still didn''t work.
> 
> Dan
Regards,

Park Heesob



--MIME Multi-part separator--

> > I tried this:
> > 
> > LPCTSTR AllocWideLPCString(VALUE rbString){
> >    char* szText = STR2CSTR(rbString);
> >    int nLen = (strlen(szText) + 1) * sizeof(LPCTSTR);
> should be
>      int nLen = (strlen(szText) + 1) * sizeof(WCHAR);
I tried both actually.  Didn''t make any difference.  For testing,
I''m
using the Eventlog.backup method.

in eventlog_backup:

// original - this works
lpBackupFileName = (LPCTSTR)STR2CSTR(rbFile);

// proposed - this doesn''t work
lpBackupFileName = AllocWideLPCString(rbFile);

I tried this simple test script:

# test_backup.rb
require "ftools"
require "win32/eventlog"
include Win32

backup_file = "C:\\event_backup2"
File.delete(backup_file) if File.exists?(backup_file)

e2 = EventLog.open("Application")
e2.backup(backup_file)
e2.close

test_backup.rb:20:in `backup'': BackupEventLog() call failed: Cannot
create a file when that file already exists. (Win32::EventLogError)
        from test_backup.rb:20

If I use the old code, it works fine.  What gives?

Dan

> > > I tried this:
> > >
> > > LPCTSTR AllocWideLPCString(VALUE rbString){
> > >    char* szText = STR2CSTR(rbString);
> > >    int nLen = (strlen(szText) + 1) * sizeof(LPCTSTR);
> > should be
> >      int nLen = (strlen(szText) + 1) * sizeof(WCHAR);
>
> I tried both actually.  Didn''t make any difference.  For testing,
I''m
> using the Eventlog.backup method.
>
> in eventlog_backup:
>
> // original - this works
> lpBackupFileName = (LPCTSTR)STR2CSTR(rbFile);
>
> // proposed - this doesn''t work
> lpBackupFileName = AllocWideLPCString(rbFile);
>
> I tried this simple test script:
>
> # test_backup.rb
> require "ftools"
> require "win32/eventlog"
> include Win32
>
> backup_file = "C:\\event_backup2"
> File.delete(backup_file) if File.exists?(backup_file)
>
> e2 = EventLog.open("Application")
> e2.backup(backup_file)
> e2.close
>
> test_backup.rb:20:in `backup'': BackupEventLog() call failed:
Cannot
> create a file when that file already exists. (Win32::EventLogError)
>         from test_backup.rb:20
>
> If I use the old code, it works fine.  What gives?
>
I mean you should use AllocWideLPCString when api require unicode string.
You don''t need to use AllocWideLPCString  if it works without it. :)

Regards,

Park Heesob