GetLastError error lookup tool source code

This snippet submitted by Ken Fitlike on 2005-01-20. It has been viewed 39838 times.
Rating of 5.8 with 185 votes

 
/*===========================================================================*/
/*
  Error code Lookup Tool
  Copyright (c) Ken Fitlike 2004
  Free to good home

  Displays the text message associated with the numerical error codes returned
  by the GetLastError api function.
  
  Notes: GWL_USERDATA used instead of GWLP_USERDATA with GetWindowLongPtr and
         SetWindowLongPtr because latter not defined for MinGW w32api 3.1; 
         the values are the same in any case.

  Disclaimer: Any problems you have with this code are just that: your 
              problems.

*/
/*===========================================================================*/
#include <windows.h>
#include <tchar.h>

/*lcc-win32 may not define LR_SHARED*/
#if !defined LR_SHARED
#define LR_SHARED 0x00008000
#endif

/*control identifiers*/
enum {
  #if defined IDC_STATIC
  #undef IDC_STATIC
  #endif
  IDC_STATIC=-1,
  IDC_ERRNUM=100,
  IDC_BTNGO,
  IDC_ERRMSG,
  IDM_HELP=40000,
  IDM_ABOUT
};
/*===========================================================================*/
LRESULT CALLBACK WndProc(HWND hwnd,UINT uMsg,WPARAM wParam,LPARAM lParam);

HACCEL BuildAccelTable(void);

void CentreWnd(HWND hwnd);
BOOL CALLBACK SetChildFonts(HWND hChild,LPARAM lParam);
void ShowErrMsg(HWND hEdit,int errnum);

void AddSysMenu(HWND hwnd);
void ShowAboutBox(HWND hParent);
void ShowHelpBox(HWND hParent);
/*===========================================================================*/
int WINAPI WinMain(HINSTANCE hInst,HINSTANCE hPrev,LPSTR pStr,int nCmd)
{
HWND       hwnd;
MSG        msg;
TCHAR      classname[]=_T("kenf's_wnd");
WNDCLASSEX wcx={0};

wcx.cbSize       =sizeof(wcx); 
wcx.lpfnWndProc  =WndProc;
wcx.hInstance    =hInst; 
wcx.hIcon        =(HICON)LoadImage(0,IDI_INFORMATION,IMAGE_ICON,0,0,LR_SHARED); 
wcx.hCursor      =(HCURSOR)LoadImage(0,IDC_ARROW,IMAGE_CURSOR,0,0,LR_SHARED);
wcx.hbrBackground=(HBRUSH)(COLOR_BTNFACE+1); 
wcx.lpszClassName=classname; 

if (RegisterClassEx(&wcx))
  {
  hwnd=CreateWindowEx(0,classname,_T("Error Message Tool"),
                      WS_OVERLAPPEDWINDOW&~WS_MAXIMIZEBOX&~WS_THICKFRAME,
                      0,
                      0,
                      278,
                      178,
                      0,0,hInst,0);
  if (hwnd)
    {
    CentreWnd(hwnd);
    ShowWindow(hwnd,nCmd);
    UpdateWindow(hwnd);
    
    while (GetMessage(&msg,0,0,0)>0)
      {
      /*retrieve and use accel table handle from main wnd user data*/
      if (!TranslateAccelerator(hwnd,(HACCEL)GetWindowLongPtr(hwnd,GWL_USERDATA),
                                &msg))
        {
        if (!IsDialogMessage(hwnd,&msg))
          {
          TranslateMessage(&msg);
          DispatchMessage(&msg);
          }
        }
      }
    return (int)msg.wParam;
    }
  else
    {
    MessageBox(0,_T("Wnd creation failure"),_T("Error"),MB_OK|MB_ICONERROR);
    return 0;
    }
  }
MessageBox(0,_T("Wnd registration failure"),_T("Error"),MB_OK|MB_ICONERROR);
return 0;
}
/*===========================================================================*/
LRESULT CALLBACK WndProc(HWND hwnd,UINT uMsg,WPARAM wParam,LPARAM lParam)
{
static HWND hEditNum,hBtnGo,hEditMsg;

switch (uMsg)
  {
  case WM_CREATE:
    {
    /*create an accelerator table and store it as the main wnd user data*/
    SetWindowLongPtr(hwnd,GWL_USERDATA,(LONG_PTR)BuildAccelTable());
    AddSysMenu(hwnd);
    hEditNum=CreateWindowEx(WS_EX_CLIENTEDGE,_T("edit"),_T("0"),
                            WS_CHILD|WS_VISIBLE|ES_NUMBER|WS_TABSTOP,
                            56,8,138,28,
                            hwnd,(HMENU)IDC_ERRNUM,GetModuleHandle(0),0);
    SendMessage(hEditNum,EM_SETLIMITTEXT,5,0);
    CreateWindowEx(0,_T("static"),_T("Value:"),
                   WS_CHILD|WS_VISIBLE|SS_CENTERIMAGE,
                   8,8,48,28,
                   hwnd,(HMENU)IDC_STATIC,GetModuleHandle(0),0);
    hBtnGo=CreateWindowEx(0,_T("button"),_T("Show"),
                          WS_VISIBLE|WS_CHILD|WS_TABSTOP,
                          208,8,56,28,
                          hwnd,(HMENU)IDC_BTNGO,GetModuleHandle(0),0);
    CreateWindowEx(0,_T("static"),_T("Message:"),
                   WS_CHILD|WS_VISIBLE|SS_CENTERIMAGE,
                   8,42,48,28,
                   hwnd,(HMENU)IDC_STATIC,GetModuleHandle(0),0);
    hEditMsg=CreateWindowEx(WS_EX_CLIENTEDGE,_T("edit"),0,
                            WS_CHILD|WS_VISIBLE|ES_MULTILINE|ES_READONLY|
                            WS_TABSTOP,
                            8,70,256,68,
                            hwnd,(HMENU)IDC_ERRNUM,GetModuleHandle(0),0);
    EnumChildWindows(hwnd,SetChildFonts,0);
    SetFocus(hEditNum);
    SendMessage(hEditNum,EM_SETSEL,0,-1);
    return 0;
    }
  case WM_COMMAND:
    {
    WORD wID,wNotify;
    
    wID=LOWORD(wParam);
    wNotify=HIWORD(wParam);
    
    if (wNotify==BN_CLICKED)
      {
      switch (wID)
        {
        case IDCANCEL:
          DestroyWindow(hwnd);
          return 0;
        case IDOK: /*'enter' key pressed when edit has focus*/
        case IDC_BTNGO:
          {
          ShowErrMsg(hEditMsg,GetDlgItemInt(hwnd,IDC_ERRNUM,0,0));
          return 0;
          }
        }
      }
    return 0;
    }
  case WM_DESTROY:
    DestroyAcceleratorTable((HACCEL)GetWindowLongPtr(hwnd,GWL_USERDATA));
    PostQuitMessage(0);
    return 0;
  case WM_SYSCOMMAND:
    {
    UINT uCmd=(UINT)wParam;
    switch (uCmd)
      {
      case IDM_ABOUT:
        ShowAboutBox(hwnd);
        return 0;
      case IDM_HELP:
        ShowHelpBox(hwnd);
        return 0;
      }
    return DefWindowProc(hwnd,uMsg,wParam,lParam);
    }
  default:
    return DefWindowProc(hwnd,uMsg,wParam,lParam);
  }
}
/*===========================================================================*/
void AddSysMenu(HWND hwnd)
{
/*retrieves copy of system (window) menu and adds a couple of options to it*/
HMENU hMenu;

hMenu=GetSystemMenu(hwnd,0);

AppendMenu(hMenu,MF_SEPARATOR,0,0);
AppendMenu(hMenu,MF_STRING,IDM_HELP,_T("Help..."));
AppendMenu(hMenu,MF_STRING,IDM_ABOUT,_T("About..."));
}
/*===========================================================================*/
HACCEL BuildAccelTable(void)
{
/*building accelerator table dynamically for simplicity of presentation 
  only - use of resources should be preferred*/
ACCEL ac;

ac.fVirt=FVIRTKEY;
ac.key=VK_F1;
ac.cmd=IDM_HELP;

return CreateAcceleratorTable(&ac,1);
}
/*===========================================================================*/
void CentreWnd(HWND hwnd)
{
/*centre wnd on desktop*/
RECT rc,rcDesk;

SystemParametersInfo(SPI_GETWORKAREA,0,&rcDesk,0);
GetWindowRect(hwnd,&rc);

MoveWindow(hwnd,(rcDesk.right-rc.right+rc.left)/2,
           (rcDesk.bottom-rc.bottom+rc.top)/2,
           rc.right-rc.left,
           rc.bottom-rc.top,0);
}
/*===========================================================================*/
BOOL CALLBACK SetChildFonts(HWND hChild,LPARAM lParam)
{
/*EnumChildProc*/
SendMessage(hChild,WM_SETFONT,(WPARAM)GetStockObject(DEFAULT_GUI_FONT),
            MAKELPARAM(1,0));
return TRUE;
}
/*===========================================================================*/
void ShowAboutBox(HWND hParent)
{
/*using MessageBoxIndirect to give option of having user defined icon - this
  option is not taken in this example */
HWND         hFocus;
int          len;
MSGBOXPARAMS mbp;
TCHAR        *txt;
TCHAR        ab[]=_T("About ");

len=lstrlen(ab)+GetWindowTextLength(hParent)+1;
if ((txt=malloc(len*sizeof(TCHAR)))!=0)
  {
  lstrcpy(txt,ab);
  GetWindowText(hParent,&txt[lstrlen(ab)],len);
  }
  
hFocus=GetFocus();

mbp.cbSize=sizeof(mbp); 
mbp.hwndOwner=hParent; 
/*if using own icon then set mbp.hInstance=GetModuleHandle(0);*/
mbp.hInstance=0;
mbp.lpszText=_T("Copyright (c) 2004\n\nKen Fitlike"); 
if (txt)
  {
  mbp.lpszCaption=txt; 
  }
else
  {
  mbp.lpszCaption=ab; 
  }
mbp.dwStyle=MB_USERICON; 
mbp.lpszIcon=IDI_INFORMATION; 
mbp.dwContextHelpId=0; 
mbp.lpfnMsgBoxCallback=0; 
mbp.dwLanguageId=MAKELANGID(LANG_ENGLISH,SUBLANG_ENGLISH_UK);
MessageBoxIndirect(&mbp);

if (txt) {free(txt);}

SetFocus(hFocus);
}
/*===========================================================================*/
void ShowErrMsg(HWND hEdit,int errnum)
{
HWND hFocus;
void *pMsg;

hFocus=GetFocus();
 
if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
                  0,
                  errnum,
                  MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
                  (LPTSTR)&pMsg,
                  0,
                  NULL)==0)
  {
  /*nothing doing*/
  MessageBox(0, _T("There is no message associated\n with that error code."),
             _T("Error"), MB_OK|MB_ICONEXCLAMATION );
  }
else
  {
  /*show it*/
  SetWindowText(hEdit,pMsg);
  LocalFree(pMsg); /*free memory*/
  }
SetFocus(hFocus);
}
/*===========================================================================*/
void ShowHelpBox(HWND hParent)
{
HWND hFocus;

hFocus=GetFocus();

MessageBox(hParent,
           _T("F1\tHelp\nESC\tQuit\n\n")
           _T("Enter numerical error code in 'value' field\n")
           _T("and click the 'show' button to display any\n")
           _T("error message that corresponds to that value.\n"),
           _T("Help"),
           MB_OK);

SetFocus(hFocus);           
}
/*===========================================================================*/




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