Windows Programming系列 ErrorShow

1、Watch窗口键入@err,hr to get latest error code and description.

2、BOOL fOk = FormatMessage(

FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,

NULL, dwError, MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),

(PTSTR) &hlocal, 0, NULL);

3、Source code:

      // Get the error code
      DWORD dwError = GetDlgItemInt(hwnd, IDC_ERRORCODE, NULL, FALSE);

      HLOCAL hlocal = NULL;   // Buffer that gets the error message string

      // Get the error code's textual description
      BOOL fOk = FormatMessage(
         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER, 
         NULL, dwError, MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), 
         (PTSTR) &hlocal, 0, NULL);

      if (!fOk) ...{
         // Is it a network-related error?
         HMODULE hDll = LoadLibraryEx(TEXT("netmsg.dll"), NULL, 
            DONT_RESOLVE_DLL_REFERENCES);

         if (hDll != NULL) ...{
            FormatMessage(
               FORMAT_MESSAGE_FROM_HMODULE | FORMAT_MESSAGE_FROM_SYSTEM,
               hDll, dwError, MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
               (PTSTR) &hlocal, 0, NULL);
            FreeLibrary(hDll);
         }
      }

      if (hlocal != NULL) ...{
         SetDlgItemText(hwnd, IDC_ERRORTEXT, (PCTSTR) LocalLock(hlocal));
         LocalFree(hlocal);
      } else ...{
         SetDlgItemText(hwnd, IDC_ERRORTEXT, TEXT("Error number not found."));
      }