file encoding detector based on Mozilla Universal Charset Detector by https://github.com/errepi/ude

DetectCharset.cs

void Main()
{
    DetectEncodings(Directory.EnumerateFiles(@"PATH to your project", "*.cs", SearchOption.AllDirectories)
        .Where(x => !x.Contains(@"\bin\") && !x.Contains(@"\obj\")))
        .Where(x => x.Charset != "UTF-8" && x.Charset != "ASCII" && x.Charset != null)
        .Dump();
}

IEnumerable<(string Path, string Charset)> DetectEncodings(IEnumerable<string> paths)
{
    var detector = new Ude.CharsetDetector();
    foreach (var path in paths)
    {
        using (var stream = File.OpenRead(path))
        {
            detector.Feed(stream);
            detector.DataEnd();
            yield return (path, detector.Charset);
            detector.Reset();
        }
    }
}