Helper to get application information

ApplicationInfo.cs

using System.Reflection;
using System.IO;
using System;
using System.Runtime.InteropServices;


namespace PMS_UI.Infrastructure.Applications
{
    /// <summary>
    /// This class provides information about the running application.
    /// </summary>
    public static class ApplicationInfo
    {
        private static readonly Lazy<string> _productName = new Lazy<string>(GetProductName);
        private static readonly Lazy<string> _version = new Lazy<string>(GetVersion);
        private static readonly Lazy<string> _company = new Lazy<string>(GetCompany);
        private static readonly Lazy<string> _copyright = new Lazy<string>(GetCopyright);
        private static readonly Lazy<string> _applicationPath = new Lazy<string>(GetApplicationPath);
        private static readonly Lazy<Guid> _applicationId = new Lazy<Guid>(GetApplicationId);
        private static readonly Lazy<Guid> _assemblyId = new Lazy<Guid>(GetAssemblyId);
        private static readonly Lazy<string> _userDataFolder = new Lazy<string>(GetUserDataFolder);
        private static readonly Lazy<string> _userRoamingDataFolder = new Lazy<string>(GetUserRoamingDataFolder);
        private static readonly Lazy<string> _allUsersDataFolder = new Lazy<string>(GetAllUsersDataFolder);

        /// <summary>
        /// Gets the product name of the application.
        /// </summary>
        public static string ProductName { get { return _productName.Value; } }

        /// <summary>
        /// Gets the version number of the application.
        /// </summary>
        public static string Version { get { return _version.Value; } }

        /// <summary>
        /// Gets the company of the application.
        /// </summary>
        public static string Company { get { return _company.Value; } }

        /// <summary>
        /// Gets the copyright information of the application.
        /// </summary>
        public static string Copyright { get { return _copyright.Value; } }

        /// <summary>
        /// Gets the path for the executable file that started the application, not including the executable name.
        /// </summary>
        public static string ApplicationPath { get { return _applicationPath.Value; } }
        
        /// <summary>
        /// Get the Application Guid
        /// </summary>
        public static Guid ApplicationId { get { return _applicationId.Value; } }

        /// <summary>
        /// Get the current assembly Guid.
        /// <remarks>
        /// Note that the Assembly Guid is not necessarily the same as the
        /// Application Guid - if this code is in a DLL, the Assembly Guid
        /// will be the Guid for the DLL, not the active EXE file.
        /// </remarks>
        /// </summary>
        public static Guid AssemblyId { get { return _assemblyId.Value; } }
       
        /// <summary>
        /// Get the current user data folder
        /// </summary>
        public static string UserDataFolder { get { return _userDataFolder.Value; } }

        /// <summary>
        /// Get the current user roaming data folder
        /// </summary>
        public static string UserRoamingDataFolder { get { return _userRoamingDataFolder.Value; } }

        /// <summary>
        /// Get all users data folder
        /// </summary>
        public static string AllUsersDataFolder { get { return _allUsersDataFolder.Value; } }

        private static string GetProductName()
        {
            Assembly entryAssembly = Assembly.GetEntryAssembly();
            if (entryAssembly != null)
            {
                AssemblyProductAttribute attribute = ((AssemblyProductAttribute)Attribute.GetCustomAttribute(
                    entryAssembly, typeof(AssemblyProductAttribute)));
                return (attribute != null) ? attribute.Product : "";
            }
            return "";
        }

        private static string GetVersion()
        {
            Assembly entryAssembly = Assembly.GetEntryAssembly();
            if (entryAssembly != null)
            {
                return entryAssembly.GetName().Version.ToString();
            }
            return "";
        }

        private static string GetCompany()
        {
            Assembly entryAssembly = Assembly.GetEntryAssembly();
            if (entryAssembly != null)
            {
                AssemblyCompanyAttribute attribute = ((AssemblyCompanyAttribute)Attribute.GetCustomAttribute(
                    entryAssembly, typeof(AssemblyCompanyAttribute)));
                return (attribute != null) ? attribute.Company : "";
            }
            return "";
        }

        private static string GetCopyright()
        {
            Assembly entryAssembly = Assembly.GetEntryAssembly();
            if (entryAssembly != null)
            {
                AssemblyCopyrightAttribute attribute = (AssemblyCopyrightAttribute)Attribute.GetCustomAttribute(
                    entryAssembly, typeof(AssemblyCopyrightAttribute));
                return attribute != null ? attribute.Copyright : "";
            }
            return "";
        }

        private static string GetApplicationPath()
        {
            Assembly entryAssembly = Assembly.GetEntryAssembly();
            if (entryAssembly != null)
            {
                return Path.GetDirectoryName(entryAssembly.Location);
            }
            return "";
        }

        private static Guid GetApplicationId()
        {
            Assembly asm = Assembly.GetEntryAssembly();
            object[] attr = (asm.GetCustomAttributes(typeof(GuidAttribute), true));
            return new Guid((attr[0] as GuidAttribute).Value);
        }

        private static Guid GetAssemblyId()
        {
            Assembly asm = Assembly.GetExecutingAssembly();
            object[] attr = (asm.GetCustomAttributes(typeof(GuidAttribute), true));
            return new Guid((attr[0] as GuidAttribute).Value);
        }

        private static string GetUserDataFolder()
        {
            Guid appGuid = ApplicationId;
            string folderBase = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
            string path = string.Format(@"{0}\{1}\", folderBase, appGuid.ToString("B").ToUpper());
            return CreatePath(path);
        }

        private static string GetUserRoamingDataFolder()
        {
            Guid appGuid = ApplicationId;
            string folderBase = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
            string path = string.Format(@"{0}\{1}\", folderBase, appGuid.ToString("B").ToUpper());
            return CreatePath(path);
        }

        private static string GetAllUsersDataFolder()
        {
            Guid appGuid = ApplicationId;
            string folderBase = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData);
            string path = string.Format(@"{0}\{1}\", folderBase, appGuid.ToString("B").ToUpper());
            return CreatePath(path);
        }
        private static string CreatePath(string path)
        {
            Directory.CreateDirectory(path);

            return path;        
        }
    }
}