LPCWSTR doesn't work with reg commands

LPCWSTR doesn't work with reg commands

• Patrick in Canada

  What is the registry type of the value you're querying, is it a REG_SZ, REG_BINARY, REG_EXPAND_SZ

  Also, now that you've corrected most of the errors, can you backup, delete and recreate the registry key with your corrected program

  
  
  

• John Holden

  

  Did you actually check rgValue between the two lines I told you to check (After RegCloseKey(hk) but before return rgValue)

  I don't think you performed what I asked (check rgValue INSIDE the function). Your latest reply indicates you've been checking rgValue from OUTSIDE the function.

  You can't read rgValue from outside the function, because rgValue is a local variable, therefore only has meaning inside that function. In order to read it outside the function, you either have to make rgValue global, or place its on dynamic memory (which is what the malloc does).

  On the second part: Don't use MessageBoxA, use MessageBoxW!

  
  
  

• Ade Morgan

  To be able to answer this one properly, we need to know what you are doing. So could you post the code that uses the RegCreateKeyEx function.
  
  

• Mike Yamashita

  Does the value look like garbage when you view it in Registry editor (regedit.exe)

  
  
  

• StuartLodge

  The type is REG_EXPAND_SZ.
  

• mike in nyc

  I have a question: does rgValue look okay in between the lines:

  RegCloseKey(hk);
  /* Over here eg. Do a OutputDebugString(), or printf here... and does it come out okay */

  return rgValue;

  
  
  

• Evenstar

  The following C++ code compiles and runs fine for me.

  ---

  #include <windows.h>
  #include <iostream>
  #include <tchar.h>

   

  wchar_t *ReadKey(wchar_t *path, wchar_t *key)
  {

    HKEY hk;
    wchar_t rgValue [1024];
    DWORD size;
    DWORD Type;

    if( RegOpenKeyEx( HKEY_LOCAL_MACHINE,path,0,KEY_QUERY_VALUE, &hk)
       == ERROR_SUCCESS)
    {

      size=1023;
      RegQueryValueEx( hk, key, NULL, &Type, (LPBYTE)rgValue, &size);

    }

    RegCloseKey(hk);
    std::wcout << rgValue << std::endl;
    return rgValue;

  }

  void WriteKey(wchar_t *path, wchar_t *name, wchar_t *value, int size)
  {
    HKEY hk;
    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, (LPCWSTR)path, 0, KEY_ALL_ACCESS, &hk))
    {
      exit(1);
    }

    if (RegSetValueEx(hk, (LPCWSTR)name, 0, REG_EXPAND_SZ, (LPBYTE)value, size))
    {
      exit(1);
    }
    RegCloseKey(hk);
  }

  void CreateKey(wchar_t *key)
  {

    HKEY hk;
    DWORD dwHappened;
    if (RegCreateKeyEx(HKEY_LOCAL_MACHINE, key, 0, NULL, REG_OPTION_NON_VOLATILE,
      KEY_WRITE, NULL, &hk, &dwHappened))
    {
    }

    RegCloseKey(hk);

  }

  int wmain(void)
  {
    CreateKey(L"SOFTWARE\\Foo");
    WriteKey(L"SOFTWARE\\Foo", L"BAR", L"Data", 4 * sizeof(wchar_t));
    ReadKey(L"SOFTWARE\\Foo", L"BAR");
    return 0;
  }

  ---

  I do not get garbage out in rgValue
  
  

• Mensana

  Well that fixed up most of my functions the only one not working is ReadKey. When I use it it returns jibberish. This is the modified function.

  "

  wchar_t* ReadKey(wchar_t* path, wchar_t* key)

  {

  HKEY hk;

  wchar_t rgValue [1024];

  DWORD size;

  DWORD Type;

  if( RegOpenKeyEx( HKEY_LOCAL_MACHINE,path,0,KEY_QUERY_VALUE, &hk) == ERROR_SUCCESS)

  {

  size=1023;

  RegQueryValueEx( hk, key, NULL, &Type,(LPBYTE)rgValue,&size);

  }

  RegCloseKey(hk);

  return rgValue;

  }

  "

  
  

• Sahikon

  OuptputDebugString() and MessageBoxA both gave me the same jibberish.
  

• Puckie Penn

  by the way after messing with my function for a bit I managed to get the first letter from my key but notning else.

  "

  wchar_t* ReadKey(wchar_t* path, wchar_t* key)

  {

  HKEY hk;

  wchar_t *rgValue;

  DWORD size;

  DWORD Type;

  if( RegOpenKeyEx( HKEY_LOCAL_MACHINE,path,0,KEY_QUERY_VALUE, &hk) == ERROR_SUCCESS)

  {

  RegQueryValueEx( hk, key, NULL, NULL,NULL,&size);

  rgValue = (wchar_t*)malloc(size);

  RegQueryValueEx( hk, key, NULL, NULL,(LPBYTE) rgValue,&size);

  }

  RegCloseKey(hk);

  return rgValue;

  }

  "

  
  

• vasko

  Here is the code for my functions

  "

  char* ReadKey(char* path, char* key)

  {

  HKEY hk;

  char rgValue [1024];

  DWORD size;

  DWORD Type;

  if( RegOpenKeyEx( HKEY_LOCAL_MACHINE,(LPCWSTR) path,0,KEY_QUERY_VALUE, &hk) == ERROR_SUCCESS)

  {

  size=1023;

  RegQueryValueEx( hk,(LPCWSTR) key, NULL, &Type,(LPBYTE)rgValue,&size);

  }

  RegCloseKey(hk);

  return rgValue;

  }

  void WriteKey(char* path, char* name, char* value, int size)

  {

  HKEY hk;

  if(RegOpenKeyEx(HKEY_LOCAL_MACHINE,(LPCWSTR) path,0,KEY_ALL_ACCESS,&hk))

  {

  exit(1);

  }

  if (RegSetValueEx(hk,(LPCWSTR) name, 0,REG_EXPAND_SZ, (LPBYTE)value,size))

  {

  exit(1);

  }

  RegCloseKey(hk);

  }

  void CreateKey(char* key)

  {

  HKEY hk;

  DWORD dwHappened;

  if (RegCreateKeyEx(HKEY_LOCAL_MACHINE,(LPCWSTR) key

  0, NULL, REG_OPTION_NON_VOLATILE,

  KEY_WRITE, NULL, &hk, &dwHappened))

  {

  }

  RegCloseKey(hk);

  }

  "

  
  

• The_S_T_

  Well I am using the form desiner so I copied just your ReadKey function and used a messagebox for my output and still got the same garbage.
  

• James Walters

  Problems similar to this have been asked before. You'll notice that the same error pops up with ::MessageBox().

  First of all, note that you cannot convert a char* to TCHAR* by using a cast (Note: LPCTSTR is typedef'ed as a TCHAR pointer NOT a char pointer). You need to alter your function to use TCHARs instead of chars.

  This is a good thread that gives the solution concisely (pay attention to the differences between Takashi's code and purplenite's code):
  http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=164510&SiteID=1

  The reason it occurs is covered here:
  http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=278234&SiteID=1

  These threads may also be useful:
  http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=279875&SiteID=1
  http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=136598&SiteID=1
  http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=268288&SiteID=1

  
  
  

• Mikeq

  Nope. It looks fine in registry Editor.
  
• LPCWSTR doesn't work with reg commands