Windows API 错误码解析
调用Windows API失败后,通常需要通过GetLastError来获取对应的错误码,要将此错误码解析为对应的描述信息,则需要调用另外一个Windows API FormatMessage,原型如下:
DWORD WINAPI FormatMessage(
_In_ DWORD dwFlags,
_In_opt_ LPCVOID lpSource,
_In_ DWORD dwMessageId,
_In_ DWORD dwLanguageId,
_Out_ LPTSTR lpBuffer,
_In_ DWORD nSize,
_In_opt_ va_list *Arguments
);
详细函数说明情况:msdn文档
具体实现代码:
/*
wstring 转换为 string
*/
std::string w2c(const wchar_t * pw)
{
std::string val = "";
if(!pw)
{
return val;
}
size_t size= wcslen(pw)*sizeof(wchar_t);
char *pc = NULL;
if(!(pc = (char*)malloc(size)))
{
return val;
}
size_t destlen = wcstombs(pc,pw,size);
/*转换不为空时,返回值为-1。如果为空,返回值0*/
if (destlen ==(size_t)(0))
{
return val;
}
val = pc;
delete pc;
return val;
}
string parseErrorCode(DWORD nErrorCode)
{
LPVOID lpMsgBuf;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL,
nErrorCode,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0, NULL );
string sMsg = w2c((LPTSTR)lpMsgBuf);
LocalFree(lpMsgBuf);
return sMsg;
}