vc++ 错误输出的有关问题

vc++ 异常输出的问题
我想把异常的信息输出来，可是怎么总也没有信息呢？我把e.Error()，e.ErrorInfo()，e.ErrorMessage()都用过，结果是：Unknown   error   0x800A151C，为什么呢？

try   {
}catch(_com_error   &   e)   {
        printf( "exception:%s ",e.ErrorMessage());
}

[解决办法]
Microsoft Specific

Retrieves the string message for HRESULT stored in the _com_error object.

const TCHAR * ErrorMessage( ) const throw( );


Return Value
Returns the string message for the HRESULT recorded within the _com_error object. If the HRESULT is a mapped 16-bit wCode, then a generic message "IDispatch error # <wCode> " is returned. If no message is found, then a generic message "Unknown error # <hresult> " is returned. The returned string is either a Unicode or multibyte string, depending on the state of the _UNICODE macro.


If no message is found, then a generic message "Unknown error # <hresult> " is returned.

意味什么？

[解决办法]
它上面的意思就是没有发现错误信息就返回“Unknown error　XXXX”.

就是你上面的那个情况。