您可以使用 stringWithContentsOfFile：usedEncoding：error：除了新的字符串，它返回使用的编码。

You can use stringWithContentsOfFile:usedEncoding:error:, which returns, in addition to the new string, the encoding that was used.

我应该注意，这是一个启发式过程本质上 - 并不总是可能确定文件的字符编码。

I should note that this is a heuristic process by nature -- it's not always possible to determine the character encoding of a file.