Remove all non-ASCII characters from string

Question

I have a C# routine that imports data from a CSV file, matches it against a database and then rewrites it to a file. The source file seems to have a few non-ASCII characters

Answer 1

string sOut = Encoding.ASCII.GetString(Encoding.ASCII.GetBytes(s))

Answer 2

Here's an improvement upon the accepted answer:

string fallbackStr = "";

Encoding enc = Encoding.GetEncoding(Encoding.ASCII.CodePage,
  new EncoderReplacementFallback(fallbackStr),
  new DecoderReplacementFallback(fallbackStr));

string cleanStr = enc.GetString(enc.GetBytes(inputStr));

This method will replace unknown characters with the value of fallbackStr, or if fallbackStr is empty, leave them out entirely. (Note that enc can be defined outside the scope of a function.)

Answer 3

If you wanted to test a specific character, you could use

if ((int)myChar <= 127)

Just getting the ASCII encoding of the string will not tell you that a specific character was non-ASCII to begin with (if you care about that). See MSDN.

Answer 4

Do it all at once

public string ReturnCleanASCII(string s)
{
    StringBuilder sb = new StringBuilder(s.Length);
    foreach(char c in s)
    {
       if((int)c > 127) // you probably don't want 127 either
          continue;
       if((int)c < 32)  // I bet you don't want control characters 
          continue;
       if(c == ',')
          continue;
       if(c == '"')
          continue;
       sb.Append(c);
    }
    return sb.ToString();
}

Answer 5

Here a simple solution:

public static bool IsASCII(this string value)
{
    // ASCII encoding replaces non-ascii with question marks, so we use UTF8 to see if multi-byte sequences are there
    return Encoding.UTF8.GetByteCount(value) == value.Length;
}

source: http://snipplr.com/view/35806/

Answer 6

    public string RunCharacterCheckASCII(string s)
    {
        string str = s;
        bool is_find = false;
        char ch;
        int ich = 0;
        try
        {
            char[] schar = str.ToCharArray();
            for (int i = 0; i < schar.Length; i++)
            {
                ch = schar[i];
                ich = (int)ch;
                if (ich > 127) // not ascii or extended ascii
                {
                    is_find = true;
                    schar[i] = '?';
                }
            }
            if (is_find)
                str = new string(schar);
        }
        catch (Exception ex)
        {
        }
        return str;
    }