Copying data(transferring) from TCHAR sstring[MAX_PATH ] to a CString str?

Posted on 2009-04-14
Last Modified: 2013-11-20
What is the exact process( show MFC code please) that I should use to transfer(copy) the data from TCHAR sstring[MAX_PATH]  to CString str?

I use CStdioFile nerely exclusively and I need my data to be contained in a CString; but RegOpenKeyEx and RegSetValue require TCHAR (I thought CString was already a TCHAR equalevant ).
Question by:LarryMillsSr
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LVL 31

Accepted Solution

Zoppo earned 300 total points
ID: 24139459
Hi LarryMillsSr,

in general you're right, CString is implemented based on TCHAR. If the functions require a TCHAR string it might be needed that you explicitley cast the CString to be a LPCTSTR. You can do this by just using a simple cast since CString has an implemented LPCTSTR-operator, so i.e. this code should IMO work:

CString str = ...;
RegOpenKeyEx( ..., (LPCTSTR)str, ... );

Hope that helps,

LVL 44

Assisted Solution

AndyAinscow earned 200 total points
ID: 24140691
I guess your problem isn't TCHAR but a mix of UNICODE and ASCII.
Have a look at mbtowcs (and associated functions to convert between the two).

ps.  psuedo code
TCHAR s[255] = _T("Hello");
CString s2(s);
s is now Hello
LVL 44

Expert Comment

ID: 24140693
sorry s2 is now Hello
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Author Comment

ID: 24142662
I tried the cast before I contacted Experts Exchange. It didn't work.  Here's a brief description of my problem:  The purchased installer sets four Register Keys as shown:
HKEY_LOCAL_MACHINE\Mills Software Solutions Inc\Notify
  Company   REG_SZ  MSS Inc
  Name         REG_SZ  John Doe
  Serial         REG_SZ  1111122222333334444455555

What I need to do in my program is capture each of these and make a duplicate of them so I can use the data in my Updates( and other stuff).  I need that data, because some of that data was entered by the User and I have no other means of retrieving it.  How do I do this in MFC?  winbase.h and windows.h are included(in a of-handed way in afxwin.h(MFC) but MFC does not allow(or I can't get it to do so) using regular RegOpenKeyEx, RegQueryValueEx, etc. . Note: my program is ANSI not UNICODE.

Author Comment

ID: 24142695
Should've been:(typo error)

HKEY_LOCAL_MACHINE\Software\Mills Software Solutions Inc\Notify

Note: CWinApp only allows entries in HKEY_CURRENT_USER.

LVL 49

Expert Comment

ID: 24142974
It is really just as direct and easy as AndyAiinscow said.
I guess you are getting errors in your calls to RegOpenKeyEx, RegQueryValueEx, etc.   If so, then please provide the error number -- the value returned by the first API function that fails.

Expert Comment

ID: 24144287
LVL 49

Expert Comment

ID: 24144448
A result of 2 is  ERROR_FILE_NOT_FOUND
You have misspelled or otherwise incorrectly entered the name of the subkey.  The way to solve this is as follows:
Open RegEdit and find the thing you want to see.  I'm thinking it will be in:
        MSS Inc
Below Notify will be the three items you want.  If you can't see them, then you are looking in the wrong place, or they have not been set.  Once you find the right place, right click Notify and choose "Copy Key Name"
Go to your program and paste it on a blank line:
Modify it by removing the root key and doubling all backslashes:
     SOFTWARE\\MSS Inc\\Notify
Now you can use it in RegOpenKeyEx and it will succeed.   See the Attached example, using a key from a common utility program.
-- Dan

void CD55Dlg::OnButton1() 
	HKEY hKey;
		"SOFTWARE\\Adobe\\Adobe Acrobat\\7.0\\Installer",
		0, KEY_QUERY_VALUE, &hKey);
	unsigned char buffer[_MAX_PATH];
	unsigned long datatype;
	unsigned long bufferlength = sizeof(buffer);
	nResult= RegQueryValueEx( hKey, "Path", NULL, &datatype, buffer, &bufferlength );
	MessageBox( (char*)buffer, "The value of 'Path' is..." );

Open in new window

LVL 44

Expert Comment

ID: 24145150
A guess - you have
"xx\yy\zz" instead of "xx\\yy\\zz" - note the double \ character

Author Comment

ID: 24147294
After you have the "root Path Key" how exactly do you obtain the four varables data? and at what point do you close the key you've opened == ie, after each valve's data is received or after all value's(4) data is received?
LVL 44

Expert Comment

ID: 24148124
open key
read value
read value
close key

else you attempt to read from a closed key - ERROR
LVL 49

Expert Comment

ID: 24152776
>>how exactly do you obtain the four varables data?
Pleasae look at the example that I provided.  The value ends up in the variablle named buffer

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