[Windows Api 学习] Error Handling Functions

BOOL WINAPI FlashWindowEx(
  __in          PFLASHWINFO pfwi
);

DWORD WINAPI FormatMessage(
  __in          DWORD dwFlags,
  __in          LPCVOID lpSource,
  __in          DWORD dwMessageId,
  __in          DWORD dwLanguageId,
  __out         LPTSTR lpBuffer,
  __in          DWORD nSize,
  __in          va_list* Arguments
);

eg. Retrieving the Last-Error Code

#include <windows.h>
#include <strsafe.h>

void ErrorExit(LPTSTR lpszFunction) 
{ 
    // Retrieve the system error message for the last-error code

    LPVOID lpMsgBuf;
    LPVOID lpDisplayBuf;
    DWORD dw = GetLastError(); 

    FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        dw,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPTSTR) &lpMsgBuf,
        0, NULL );

    // Display the error message and exit the process

    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT, 
        (lstrlen((LPCTSTR)lpMsgBuf)+lstrlen((LPCTSTR)lpszFunction)+40)*sizeof(TCHAR)); 
    StringCchPrintf((LPTSTR)lpDisplayBuf, 
        LocalSize(lpDisplayBuf),
        TEXT("%s failed with error %d: %s"), 
        lpszFunction, dw, lpMsgBuf); 
    MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK); 

    LocalFree(lpMsgBuf);
    LocalFree(lpDisplayBuf);
    ExitProcess(dw); 
}

void main()
{
    // Generate an error

    if(!GetProcessId(NULL))
        ErrorExit(TEXT("GetProcessId"));
}