How get list of codepages from string

Question

I have string with different codepages: string multi = "EnglishРусский日本語";

I need to return list of codepages:

int[] GetCodePage(string multi)
{
   return new int[] {1252, 1251, 932};
}

Answer 1

From your comments, it seems that your problem is different.

If you only need to check if a filename (a string) uses only characters from the "default codepage" (the Windows api uses unicode plus a single non unicode codepage, that is the default codepage for non-unicode programs), then it is quite simple. Encoding.Default is the Windows non-unicode codepage.

public static void Main()
{
    Console.WriteLine(Encoding.Default.BodyName);

    // I live in Italy, we use the Windows-1252 as the default codepage 
    Console.WriteLine(CanBeEncoded(Encoding.Default, "Hello world àèéìòù"));

    Console.WriteLine(CanBeEncoded(Encoding.Default, "Русский"));
}

and the interesting code:

public static bool CanBeEncoded(Encoding enc, string str)
{
    // We want to modify the Encoding, so we have to clone it
    enc = (Encoding)enc.Clone();
    enc.EncoderFallback = new EncoderExceptionFallback();

    try
    {
        enc.GetByteCount(str);
    }
    catch (EncoderFallbackException)
    {
        return false;
    }

    return true;        
}

Note that this code could be optimized. Using an exception to check for the fact that the string can be encoded isn't optimal (but it is easy to write :-) ). A better solution would be to subclass the EncoderFallback class.