C# 根据文件头判断文件类型

根据文件头判断文件类型

参考:255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar 其他类型应该网上能查到叭，，我这就懒得去找了

        public static bool IsPicture(string filePath)
        {
            try
            {
                using (var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
                {
                    using (var reader = new BinaryReader(fs))
                    {
                        string fileClass;
                        byte buffer;
                        buffer = reader.ReadByte();
                        fileClass = buffer.ToString();
                        buffer = reader.ReadByte();
                        fileClass += buffer.ToString();
                        reader.Close();
                        fs.Close();
                        //255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar
                        switch (fileClass)
                        {
                            case "255216":
                            case "7173":
                            case "13780":
                            case "6677":
                                return true;
                            default:
                                return false;
                        }
                    }
                }
            }
            catch
            {
                return false;
            }
        }