当使用单字节字符时，ASCII格式定义了前127个字符。128-255的扩展字符由各种ANSI代码页定义，以允许对其他语言的有限支持。为了理解ANSI编码的字符串，您需要知道它使用哪个代码页。

基本上“ANSI”指的是Windows上的遗留代码页。请参阅Raymond Chen关于此主题的文章:

这是因为Windows代码页1252最初是基于ANSI草案，后来成为ISO标准8859-1。

在大多数代码页中，前127个字符与ASCII相同，但上面的字符有所不同。

然而，ANSI并不自动表示CP1252或拉丁1。

尽管有很多困惑，但您现在应该简单地避免这些问题，并使用Unicode。

严格地说，没有所谓的ANSI编码。通俗地说，术语ANSI用于几种不同的编码:

ISO 8859 - 1 Windows CP1252 Windows机器上的当前系统编码(用Win32 API术语)。

我记得当“ANSI”文本引用伪VT-100转义码通过ANSI在DOS中可用。SYS驱动程序来改变流文本....可能不是你指的，但如果是，请参阅http://en.wikipedia.org/wiki/ANSI_escape_code

Once upon a time Microsoft, like everyone else, used 7-bit character sets, and they invented their own when it suited them, though they kept ASCII as a core subset. Then they realised the world had moved on to 8-bit encodings and that there were international standards around, such as the ISO-8859 family. In those days, if you wanted to get hold of an international standard and you lived in the US, you bought it from the American National Standards Institute, ANSI, who republished international standards with their own branding and numbers (that's because the US government wants conformance to American standards, not international standards). So Microsoft's copy of ISO-8859 said "ANSI" on the cover. And because Microsoft weren't very used to standards in those days, they didn't realise that ANSI published lots of other standards as well. So they referred to the standards in the ISO-8859 family (and the variants that they invented, because they didn't really understand standards in those days) by the name on the cover, "ANSI", and it found its way into Microsoft user documentation and hence into the user community. That was about 30 years ago, but you still sometimes hear the name today.

ANSI(又名Windows-1252/WinLatin1)是拉丁字母的字符编码，非常类似于ISO-8859-1。 你可以去维基百科上看看。