替换不能做文件名的字符

MakeValidFileName.cs

       public static string MakeValidFileName(string text, string replacement = "_")
        {
            StringBuilder str=new StringBuilder();
            var invalidFileNameChars = System.IO.Path.GetInvalidFileNameChars();
            foreach (var c in text)
            {
                if (invalidFileNameChars.Contains(c))
                {
                    str.Append(replacement??"");
                }
                else
                {
                    str.Append(c);
                }
            }

            return str.ToString();
        }