Visual Application Launcher

namespace VAL
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Drawing;
    using System.Runtime.InteropServices;

    /// <summary>
    /// Simple class to define some of the information required to display file
    /// information
    /// </summary>
    public class KnownExplorerFile
    {
        /// <summary>
        /// Default ctor
        /// </summary>
        /// <param name="description">The description of the file type</param>
        /// <param name="icon">The icon for the file type</param>
        public KnownExplorerFile(string description, Icon icon)
        {
            this.TypeDescription = description;
            this.Icon = icon;
        }

        /// <summary>
        /// The description of the file as seen in windows explorer
        /// </summary>
        public string TypeDescription { get; private set; }

        /// <summary>
        /// An icon associated with a file type
        /// </summary>
        public Icon Icon { get; private set; }



        /// <summary>
        /// Method that returns information about a particular file
        /// <para>
        /// This will get the file type description (as seen in windows explorer) and the 
        /// icon associated with the file type
        /// </para>
        /// </summary>
        /// <param name="fileName">The filename to retrieve information about</param>
        /// <returns>A <see cref="KnownExplorerFile"/> object</returns>
        public static KnownExplorerFile GetInstance(string fileName)
        {
            NativeMethods.SHFILEINFO shinfo = new NativeMethods.SHFILEINFO();
            IntPtr fi;
            /*
             Type: DWORD_PTR
             Returns a value whose meaning depends on the uFlags parameter.
             If uFlags does not contain SHGFI_EXETYPE or SHGFI_SYSICONINDEX, 
             the return value is nonzero if successful, or zero otherwise.
            */
            fi = NativeMethods.SHGetFileInfo(fileName, 0, ref shinfo,
                             (uint)Marshal.SizeOf(shinfo),
                              SHGetFileInfoFlags.SHGFI_ICON |
                              SHGetFileInfoFlags.SHGFI_TYPENAME);

            KnownExplorerFile knownFile = null;
            if (fi.ToInt32() != 0)
            {
                // Clone the icon from handle, then clean up  
                Icon fileIcon = (Icon)Icon.FromHandle(shinfo.hIcon).Clone();
                NativeMethods.DestroyIcon(shinfo.hIcon);

                string fileType = shinfo.szTypeName;
                knownFile = new KnownExplorerFile(fileType, fileIcon);
            }
            else
            {
                knownFile = new KnownExplorerFile("Unknown", null);
            }
            return knownFile;
        }

        /// <summary>
        /// Gets the file type description for the specified file
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public static string GetFileTypeDescription(string fileName)
        {
            NativeMethods.SHFILEINFO shinfo = new NativeMethods.SHFILEINFO();
            IntPtr fi;
            string fileType = string.Empty;

            fi = NativeMethods.SHGetFileInfo(fileName, 0, ref shinfo,
                             (uint)Marshal.SizeOf(shinfo),
                              SHGetFileInfoFlags.SHGFI_TYPENAME);

            if (fi.ToInt32() != 0)
                fileType = shinfo.szTypeName;

            return fileType;
        }
    }
}