从字符串中删除非ascii字符[英] Removing non-ascii characters from a string

问题描述

Hi there,

I believe all strings in .net are unicode by default, I am looking for a
way to remove all non ascii characters from a string (or optionally
replace them).

There is an article on code project which kind of looks like it does
what I want but I can''t help thinking it makes it more complex than it
needs to be.

I have looked at the msdn pages to do with Encodings but I am not very
familiar with this topic.

If I can get a list of ascii characters then it should be easy to write
a method that checks each char against the list and performs the replace
or remove operation if necessary. Yet I can''t find anything exactly
like this with trusty old google, is there something I am missing ?.

If it helps the reason I need this is because I am writing a front end
for the lame command line mp3 encoder, it doesn''t like being passed, or
asked to output to, file paths containing unicode characters.

--
Eps

推荐答案

"Eps" <ms**********@epscylonb.comwrote in message
news:er*************@TK2MSFTNGP05.phx.gbl...

Hi there,

I believe all strings in .net are unicode by default, I am looking for a
way to remove all non ascii characters from a string (or optionally
replace them).

There is an article on code project which kind of looks like it does
what I want but I can''t help thinking it makes it more complex than it
needs to be.

I have looked at the msdn pages to do with Encodings but I am not very
familiar with this topic.

If I can get a list of ascii characters then it should be easy to write
a method that checks each char against the list and performs the replace
or remove operation if necessary. Yet I can''t find anything exactly
like this with trusty old google, is there something I am missing ?.

If it helps the reason I need this is because I am writing a front end
for the lame command line mp3 encoder, it doesn''t like being passed, or
asked to output to, file paths containing unicode characters.

Perhaps I''m missing something this code:-

byte[] asciiChars = Encoding.ASCII.GetBytes("AB ￡ CD");
string result = Encoding.ASCII.GetString(asciiChars);
Console.WriteLine(result);

creates the string:-

AB ? CD

--
Anthony Jones - MVP ASP/ASP.NET

Anthony Jones wrote:

Perhaps I''m missing something this code:-

byte[] asciiChars = Encoding.ASCII.GetBytes("AB ￡ CD");
string result = Encoding.ASCII.GetString(asciiChars);
Console.WriteLine(result);

creates the string:-

AB ? CD

I have seen this code before, can anyone explain why the
Encoding.ASCII.GetString() method does not accept a string as a parameter ?.

--
Eps

On Aug 29, 1:12*pm, Eps <msnewsgro...@epscylonb.comwrote:

* * byte[] asciiChars = Encoding.ASCII.GetBytes("AB ￡ CD");
* * string result = Encoding.ASCII.GetString(asciiChars);
* * Console.WriteLine(result);

creates the string:-

AB ? CD

I have seen this code before, can anyone explain why the
Encoding.ASCII.GetString() method does not accept a string as a parameter?.

Because Encoding classes encode and decode CLR strings (which are
_always_ Unicode) to/from byte arrays in specified encoding, typically
for serialization or interop purposes. There''s no such thing as a non-
Unicode System.String (well, you could treat a string as a plain array
of char, but any .NET function will still treat string as UTF-16).

What you ask is still possible, because ASCII is a pure subset of
Unicode. With LINQ, you could use this one-liner:

string ascii = new string(s.Where(c =(int)c >= 0 && (int)c <=
127).ToArray());

Note however that "ascii" would still be a Unicode string - it just
wouldn''t contain any non-ASCII characters.