MSDN中查到这样的话:Also, in text mode, carriage return–linefeed combinations are translated into single linefeeds on input, and linefeed characters are translated to carriage return–linefeed combinations on output. (输入的情况下,换行回车转换成换行,然后输出时换行又会转成换行回车)When a Unicode stream-I/O function operates in text mode (the default), the source or destination stream is assumed to be a sequence of multibyte characters. Therefore, the Unicode stream-input functions convert multibyte characters to wide characters. For the same reason, the Unicode stream-output functions convert wide characters to multibyte characters.
详细出处参考:
http://www.jb51.net/article/26547.htm