Class for Save/Load warcraft 3 models with MDXLIB

 static class ModelSaverLoader
 {
     public static CModel? Load(string FromFileName)
     {
         CModel TemporaryModel = new CModel();
         string extension = System.IO.Path.GetExtension(FromFileName).ToLower();
         if (extension == ".mdx")
         {
             try
             {
                 using (var Stream = new System.IO.FileStream(FromFileName, System.IO.FileMode.Open, System.IO.FileAccess.Read))
                 {
                     var ModelFormat = new MdxLib.ModelFormats.CMdx();
                     ModelFormat.Load(FromFileName, Stream, TemporaryModel);
                 }
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.ToString(), $"Exception occured while trying to open {FromFileName}");
                 // CurrentModel = new CModel();
                 return null;
             }
         }
         if (extension == ".mdl")
         {
             try
             {
                 using (var Stream = new System.IO.FileStream(FromFileName, System.IO.FileMode.Open, System.IO.FileAccess.Read))
                 {
                     var ModelFormat = new MdxLib.ModelFormats.CMdl();
                     ModelFormat.Load(FromFileName, Stream, TemporaryModel);
                 }
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.ToString(), $"Exception occured while trying to open {FromFileName}");
                 //  CurrentModel = new CModel();
                 return null;
             }
         }
         return TemporaryModel;
     }
     internal static void Save(CModel model, string file)
     {
         if (file.Length == 0) { MessageBox.Show("Empty save path"); return; }
         if (
            (System.IO.Path.GetExtension(file) == ".mdx" ||
             System.IO.Path.GetExtension(file) == ".mdl") == false
             ) { MessageBox.Show("Invalid extension"); return; }
         if (model == null) { MessageBox.Show("Null model"); return; }
         if (System.IO.Path.GetExtension(file).ToLower() == ".mdl")
         {
             string ToFileName = file;
             using (var Stream = new System.IO.FileStream(ToFileName, System.IO.FileMode.Create, System.IO.FileAccess.Write))
             {
                 var ModelFormat = new MdxLib.ModelFormats.CMdl();
                 ModelFormat.Save(ToFileName, Stream, model);
             }
             FileCleaner.CleanFile(ToFileName);
         }
         if (System.IO.Path.GetExtension(file).ToLower() == ".mdx")
         {
             string ToFileName = file;
             using (var Stream = new System.IO.FileStream(ToFileName, System.IO.FileMode.Create, System.IO.FileAccess.Write))
             {
                 var ModelFormat = new MdxLib.ModelFormats.CMdx();
                 ModelFormat.Save(ToFileName, Stream, model);
             }
         }
     }
 }
public class FileCleaner
{
    public static void CleanFile(string filePath)
    {
        // Read the file content
        string content = File.ReadAllText(filePath);
        // Define the valid character set
        StringBuilder cleanedContent = new StringBuilder();
        foreach (char c in content)
        {
            if (IsValidCharacter(c))
            {
                cleanedContent.Append(c);
            }
        }
        // Delete the original file
        File.Delete(filePath);
        // Write the cleaned content to a new file
        File.WriteAllText(filePath, cleanedContent.ToString());
    }
    private static bool IsValidCharacter(char c)
    {
        // Check if the character is a valid English letter, symbol, digit, tab, or newline
        return char.IsLetterOrDigit(c) ||
               char.IsWhiteSpace(c) ||  // This includes tabs, spaces, and all other whitespaces
               c == '\n' || c == '\r' || // Newline and Carriage return
               IsValidSymbol(c);
    }
    private static bool IsValidSymbol(char c)
    {
        // Define the valid symbols (you can extend this list if needed)
        char[] validSymbols = new char[]
        {
            '!', '"', '#', '$', '%', '&', '(', ')', '*', '+', ',', '-', '.', '/',
            ':', ';', '<', '=', '>', '?', '@', '[', '\\', ']', '^', '_', '`', '{',
            '|', '}', '~'
        };
        foreach (char symbol in validSymbols)
        {
            if (c == symbol)
            {
                return true;
            }
        }
        return false;
    }
}