C# compare different Encoding pattern between UTF8 and UTF32 based on Md5

 using System;
 using System.Text;
 using System.IO;
 using System.Security.Cryptography;
 
  static void Main(string[] args)
         {
             CompareFileGetBytes("lyf.txt");
             Console.ReadLine();
         }
 
  static void CompareFileGetBytes(string fileFullName)
         {
             byte[] fileReadAllBytes = File.ReadAllBytes(fileFullName);
             string fileReadAllBytesMd5 = GetBytesMd5(fileReadAllBytes);
 
             string utf8Md5 = string.Empty;
             using (StreamReader reader = new StreamReader(fileFullName))
             {
                 string textResult = reader.ReadToEnd();
                 byte[] utf8Bytes = Encoding.UTF8.GetBytes(textResult);
                 utf8Md5 = GetBytesMd5(utf8Bytes);
             }
 
             string utf32Md5 = string.Empty;
             using (StreamReader utf32Reader = new StreamReader(fileFullName))
             {
                 string textResult = utf32Reader.ReadToEnd();
                 byte[] utf32Bytes = Encoding.UTF32.GetBytes(textResult);
                 utf32Md5 = GetBytesMd5(utf32Bytes);
             }
 
             Console.WriteLine($"fileReadAllBytesMd5:{fileReadAllBytesMd5},utf8Md5:{utf8Md5}");
 
             if (string.Equals(fileReadAllBytesMd5, utf8Md5))
             {
                 Console.WriteLine($"{nameof(fileReadAllBytesMd5)} is equal with {nameof(utf8Md5)}!");
             }
             else
             {
                 Console.WriteLine($"{nameof(fileReadAllBytesMd5)} is not equal with {nameof(utf8Md5)}!");
             }
 
             Console.WriteLine($"utf8Md5:{utf8Md5},utf32Md5:{utf32Md5}");
             if (string.Equals(utf8Md5, utf32Md5))
             {
                 Console.WriteLine($"{nameof(utf8Md5)} is equals with {nameof(utf32Md5)}");
             }
             else
             {
                 Console.WriteLine($"{nameof(utf8Md5)} is not  equals with {nameof(utf32Md5)}");
             }
         }
 
         static string GetBytesMd5(byte[] bytesData)
         {
             StringBuilder md5Builder = new StringBuilder();
             using(MD5CryptoServiceProvider md5=new MD5CryptoServiceProvider())
             {
                 byte[] md5Bytes = md5.ComputeHash(bytesData);
                 for(int i=;i<md5Bytes.Length;i++)
                 {
                     md5Builder.Append(md5Bytes[i].ToString("x2"));
                 }
             }
             return md5Builder.ToString();
         }

I had validated that different encoding mode can generate different result,they are not identical.

Besides,the File.ReadAllBytes may based on UTF8 because they render the identical result!