GetLastError error lookup tool source code
This snippet submitted by Ken Fitlike on 2005-01-20. It has been viewed 47476 times.
Rating of 5.4 with 245 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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