Question

There is a REG_MULTI_SZ value that I would like to stick in an array of strings so that my program can do other things with them. I’ve never used C++ to access the registry so I’m a bit lost after following some examples. I’m using VS10.

Is there a simple way to do this? Thanks.

Answer 1

First: run RegQueryValueEx to get type and necessary memory size:

Single byte code:

DWORD type, size;
vector<string> target;
if ( RegQueryValueExA(
    your_key, // HKEY
    TEXT("ValueName"),
    NULL,
    &type,
    NULL,
    &size ) != ERROR_SUCCESS )
  return;
if ( type == REG_MULTI_SZ )
{
  vector<char> temp(size);

  if ( RegQueryValueExA(
      your_key, // HKEY
      TEXT("ValueName"),
      NULL,
      NULL,
      reinterpret_cast<LPBYTE>(&temp[0]),
      &size ) != ERROR_SUCCESS )
  return;

  size_t index = 0;
  size_t len = strlen( &temp[0] );
  while ( len > 0 )
  {
    target.push_back(&temp[index]);
    index += len + 1;
    len = strlen( &temp[index] );
  }
}

Unicode:

DWORD type, size;
vector<wstring> target;
if ( RegQueryValueExW(
    your_key, // HKEY
    TEXT("ValueName"),
    NULL,
    &type,
    NULL,
    &size ) != ERROR_SUCCESS )
  return;
if ( type == REG_MULTI_SZ )
{
  vector<wchar_t> temp(size/sizeof(wchar_t));

  if ( RegQueryValueExW(
      your_key, // HKEY
      TEXT("ValueName"),
      NULL,
      NULL,
      reinterpret_cast<LPBYTE>(&temp[0]),
      &size ) != ERROR_SUCCESS )
  return;

  size_t index = 0;
  size_t len = wcslen( &temp[0] );
  while ( len > 0 )
  {
    target.push_back(&temp[index]);
    index += len + 1;
    len = wcslen( &temp[index] );
  }
}