windows核心编程---错误处理
如果我们自己写程序的时候检测到一个错误的时候，可能希望向用户显示错误的文本表述，而不是一个干巴巴的错误代码windows提供了一个函数可以将错误代码转换成错误文本描述，这个函数是FormatMessage。
TheFormatMessage function formats a message string. The function requires a message definition as input. The message definition can come from a buffer passed into the function. It can come from a message table resource in an already-loaded module. Or the caller can ask the function to search the system's message table resource(s) for the message definition. The function finds the message definition in a message table resource based on a message identifier and a language identifier. The function copies the formatted message text to an output buffer, processing any embedded insert sequences if requested.
#include <windows.h>#include "resource.h"LRESULT CALLBACK DialogProc(HWND ,UINT,WPARAM,LPARAM) ;void OnInitDialog(HWND hDlg);void OnOK(HWND hDlg);int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) { MSG msg;HWND hwnd = CreateDialog(hInstance, MAKEINTRESOURCE(IDD_DIALOG1), NULL, (DLGPROC)DialogProc); ShowWindow(hwnd, SW_SHOW); UpdateWindow(hwnd); while(GetMessage(&msg, NULL, 0, 0)) { if( !IsDialogMessage( hwnd, &msg ) ){TranslateMessage(&msg);DispatchMessage(&msg); }} return msg.wParam; }LRESULT CALLBACK DialogProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam) { switch(uMsg) { case WM_INITDIALOG: OnInitDialog(hWnd);SetWindowPos(hWnd,NULL,500,200,0,0,SWP_NOSIZE); return TRUE; case WM_COMMAND: if(LOWORD(wParam) == IDOK) { OnOK(hWnd); return TRUE; }if(LOWORD(wParam) == IDCANCEL){PostQuitMessage(0);return TRUE;}break; case WM_DESTROY: PostQuitMessage(0); break; } return FALSE;}void OnInitDialog(HWND hDlg){SendMessage(hDlg, WM_SETICON, ICON_SMALL, (LPARAM)LoadIcon(NULL, MAKEINTRESOURCE(IDI_ICON1)));SendMessage(hDlg, WM_SETICON, ICON_BIG, (LPARAM)LoadIcon(NULL, MAKEINTRESOURCE(IDI_ICON1)));SetDlgItemInt(hDlg, IDC_ERRORCODE, 0, FALSE);}void OnOK(HWND hDlg){DWORD dwError = GetDlgItemInt(hDlg,IDC_ERRORCODE,NULL, FALSE);LPVOID lpMsgBuf;FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,NULL,dwError,MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language(PTSTR)&lpMsgBuf, 0,NULL );SetDlgItemText(hDlg,IDC_ERRORTEXT,(PCTSTR)lpMsgBuf);// Free the buffer.LocalFree(lpMsgBuf);}