1,windows对程序错误的处理，
int APIENTRY _tWinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPTSTR lpCmdLine,int nCmdShow)
{
LPVOID lpMsgBuf;
HANDLE hFile = ::CreateFile(_T("C:\\12.txt"),0,0,NULL,OPEN_EXISTING,0,NULL);//打开文件
if(INVALID_HANDLE_VALUE==hFile)
{//文件不存在
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(),0, (LPTSTR) &lpMsgBuf,0,NULL);
MessageBox( NULL, (LPCWSTR)lpMsgBuf, _T("错误信息"), MB_OK | MB_ICONINFORMATION );
LocalFree( lpMsgBuf );
}
return 0;
}
调试时，在Watch窗口输入“@err,hr”,就可以显示线程的最后错误代码的号码和该错误的描述信息。
2008060701.jpg
VC6.0还带了一个实用小程序，可以用来将错误代码转换为相应的文本描述信息。
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书中给出了一个模仿VC6自带的那个Error Lookup实用程序的示例：
#define ESM_POKECODEANDLOOKUP (WM_USER + 100) //用户自定义消息
const TCHAR g_szAppName[] = TEXT("Error Show");
BOOL Dlg_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam)
{
chSETDLGICONS(hwnd, IDI_ERRORSHOW);//设置图标
// Don't accept error codes more than 5 digits long
Edit_LimitText(GetDlgItem(hwnd, IDC_ERRORCODE), 5);//限制输入字符长度最大为
// Look up the command-line passed error number
SendMessage(hwnd, ESM_POKECODEANDLOOKUP, lParam, 0);//发送初始错误代码消息
return(TRUE);
}
void Dlg_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) {
switch (id)
{
case IDCANCEL:
EndDialog(hwnd, id);//关闭对话框窗口
break;
case IDC_ALWAYSONTOP://始终在最前
SetWindowPos(hwnd, IsDlgButtonChecked(hwnd, IDC_ALWAYSONTOP) ? HWND_TOPMOST : HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
break;
case IDC_ERRORCODE:
EnableWindow(GetDlgItem(hwnd, IDOK), Edit_GetTextLength(hwndCtl) > 0);//设置“lookup"按钮是否enable
break;
case IDOK:
// Get the error code
DWORD dwError = GetDlgItemInt(hwnd, IDC_ERRORCODE, NULL, FALSE);//获取错误代码号码
HLOCAL hlocal = NULL; // Buffer that gets the error message string
// Use the default system locale since we look for Windows messages.
// Note: this MAKELANGID combination has 0 as value
DWORD systemLocale = MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL);//本地语言
// Get the error code's textual description
BOOL fOk = FormatMessage(
FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS |
FORMAT_MESSAGE_ALLOCATE_BUFFER,
NULL, dwError, systemLocale,
(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)
{
fOk = FormatMessage(
FORMAT_MESSAGE_FROM_HMODULE | FORMAT_MESSAGE_IGNORE_INSERTS |
FORMAT_MESSAGE_ALLOCATE_BUFFER,
hDll, dwError, systemLocale,
(PTSTR) &hlocal, 0, NULL);
FreeLibrary(hDll);
}
}
if (fOk && (hlocal != NULL))
{
SetDlgItemText(hwnd, IDC_ERRORTEXT, (PCTSTR) LocalLock(hlocal));
LocalFree(hlocal);
}
else
{
SetDlgItemText(hwnd, IDC_ERRORTEXT, TEXT("No text found for this error number."));
}
break;
}
}
INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
chHANDLE_DLGMSG(hwnd, WM_INITDIALOG, Dlg_OnInitDialog);//初始化处理
chHANDLE_DLGMSG(hwnd, WM_COMMAND, Dlg_OnCommand);//命令处理
case ESM_POKECODEANDLOOKUP:
SetDlgItemInt(hwnd, IDC_ERRORCODE, (UINT) wParam, FALSE);//控件上设置错误代码
FORWARD_WM_COMMAND(hwnd, IDOK, GetDlgItem(hwnd, IDOK), BN_CLICKED, PostMessage);//模拟按钮点击事件
SetForegroundWindow(hwnd);//设置为最前的窗口
break;
}
return(FALSE);
}
int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int)
{
HWND hwnd = FindWindow(TEXT("#32770"), TEXT("Error Show"));//寻址窗口
if (IsWindow(hwnd))
{//已经存在
// An instance is already running, activate it and send it the new #
SendMessage(hwnd, ESM_POKECODEANDLOOKUP, _ttoi(pszCmdLine), 0);
}
else
{//新窗口
DialogBoxParam(hinstExe, MAKEINTRESOURCE(IDD_ERRORSHOW),NULL, Dlg_Proc, _ttoi(pszCmdLine));
}
return(0);
}
这里用到了几个宏定义，下面这个是用来指定消息处理函数的
// The normal HANDLE_MSG macro in WindowsX.h does not work properly for dialog
// boxes because DlgProc returns a BOOL instead of an LRESULT (like
// WndProcs). This chHANDLE_DLGMSG macro corrects the problem:
#define chHANDLE_DLGMSG(hWnd, message, fn) \
case (message): return (SetDlgMsgResult(hWnd, uMsg, \
HANDLE_##message((hWnd), (wParam), (lParam), (fn))))
下面这个是用来为窗口设置大/小图标
// Sets the dialog box icons
inline void chSETDLGICONS(HWND hWnd, int idi)
{
SendMessage(hWnd, WM_SETICON, ICON_BIG, (LPARAM)
LoadIcon((HINSTANCE) GetWindowLongPtr(hWnd, GWLP_HINSTANCE),
MAKEINTRESOURCE(idi)));
SendMessage(hWnd, WM_SETICON, ICON_SMALL, (LPARAM)
LoadIcon((HINSTANCE) GetWindowLongPtr(hWnd, GWLP_HINSTANCE),
MAKEINTRESOURCE(idi)));
}
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2008/06/07/1215565.html，如需转载请自行联系原作者
