How to detect encoding file in ANSI, UTF8 and UTF8 without BOM

Question

Hi all,
I am having a problem with detecting a .txt/.csv file encoding. I need to detect a file in ANSI, UTF8 and UTF8 without BOM but the problem is the encoding of ANSI and UTF8 without BOM are the same. I checked the function below and saw that ANSI and UTF8
without BOM have the same encoding. so, How can I detect UTF8 without BOM encoding file? because I need to handle for this case in my code.
Thanks.
public Encoding GetFileEncoding(string srcFile)
            // *** Use Default of Encoding.Default (Ansi CodePage)
            Encoding enc = Encoding.Default;
            // *** Detect byte order mark if any - otherwise assume default
            byte[] buffer = new byte[10];
            FileStream file = new FileStream(srcFile, FileMode.Open);
            file.Read(buffer, 0, 10);
            file.Close();
            if (buffer[0] == 0xef && buffer[1] == 0xbb && buffer[2] == 0xbf)
                enc = Encoding.UTF8;
            else if (buffer[0] == 0xfe && buffer[1] == 0xff)
                enc = Encoding.Unicode;
            else if (buffer[0] == 0 && buffer[1] == 0 && buffer[2] == 0xfe && buffer[3] == 0xff)
                enc = Encoding.UTF32;
            else if (buffer[0] == 0x2b && buffer[1] == 0x2f && buffer[2] == 0x76)
                enc = Encoding.UTF7;
            else if (buffer[0] == 0xFE && buffer[1] == 0xFF)
                // 1201 unicodeFFFE Unicode (Big-Endian)
                enc = Encoding.GetEncoding(1201);
            else if (buffer[0] == 0xFF && buffer[1] == 0xFE)
                // 1200 utf-16 Unicode
                enc = Encoding.GetEncoding(1200);
            return enc;

Answer 1

what you want is to get the encoding utf-8 without bom which can only be detected if the file has special characters, so do the following:
public Encoding GetFileEncoding(string srcFile)
            // *** Use Default of Encoding.Default (Ansi CodePage)
            Encoding enc = Encoding.Default;
            // *** Detect byte order mark if any - otherwise assume default
            byte[] buffer = new byte[10];
            FileStream file = new FileStream(srcFile, FileMode.Open);
            file.Read(buffer, 0, 10);
            file.Close();
            if (buffer[0] == 0xef && buffer[1] == 0xbb && buffer[2]
== 0xbf)
                enc = Encoding.UTF8;
            else if (buffer[0] == 0xfe && buffer[1] == 0xff)
                enc = Encoding.Unicode;
            else if (buffer[0] == 0 && buffer[1] == 0 && buffer[2]
== 0xfe && buffer[3] == 0xff)
                enc = Encoding.UTF32;
            else if (buffer[0] == 0x2b && buffer[1] == 0x2f &&
buffer[2] == 0x76)
                enc = Encoding.UTF7;
            else if (buffer[0] == 0xFE && buffer[1] == 0xFF)
                // 1201 unicodeFFFE Unicode (Big-Endian)
                enc = Encoding.GetEncoding(1201);
            else if (buffer[0] == 0xFF && buffer[1] == 0xFE)
                // 1200 utf-16 Unicode
                enc = Encoding.GetEncoding(1200);
           else if (validatUtf8whitBOM(srcFile))
                enc = UTF8Encoding(false);
            return enc;
private bool validateUtf8whitBOM(string FileSource)
            bool bReturn = false;
            string TextUTF8 = "", TextANSI = "";
            //lread the file as utf8
           StreamReader srFileWhitBOM  = new StreamReader(FileSource);
           TextUTF8 = srFileWhitBOM .ReadToEnd();
           srFileWhitBOM .Close();
            //lread the file as  ANSI
           StreamReader srFileWhitBOM  = new StreamReader(FileSource,Encoding.Defaul,false);
           TextANSI  = srFileWhitBOM .ReadToEnd();
           srFileWhitBOM .Close();
           // if the file contains special characters is UTF8 text read ansi show signs
            if(TextANSI.Contains("Ã") || TextANSI.Contains("±")
                 bReturn = true;
            return bReturn;