﻿using System;
using System.Runtime.InteropServices;
public static class Interop
{
    /// <summary>Maximal Length of unmanaged Windows-Path-strings</summary>
    private const int MAX_PATH = 260;
    /// <summary>Maximal Length of unmanaged Typename</summary>
    private const int MAX_TYPE = 80;


    [Flags]
    public enum SHGFI : int
    {
        /// <summary>get icon</summary>
        Icon = 0x000000100,
        /// <summary>get display name</summary>
        DisplayName = 0x000000200,
        /// <summary>get type name</summary>
        TypeName = 0x000000400,
        /// <summary>get attributes</summary>
        Attributes = 0x000000800,
        /// <summary>get icon location</summary>
        IconLocation = 0x000001000,
        /// <summary>return exe type</summary>
        ExeType = 0x000002000,
        /// <summary>get system icon index</summary>
        SysIconIndex = 0x000004000,
        /// <summary>put a link overlay on icon</summary>
        LinkOverlay = 0x000008000,
        /// <summary>show icon in selected state</summary>
        Selected = 0x000010000,
        /// <summary>get only specified attributes</summary>
        Attr_Specified = 0x000020000,
        /// <summary>get large icon</summary>
        LargeIcon = 0x000000000,
        /// <summary>get small icon</summary>
        SmallIcon = 0x000000001,
        /// <summary>get open icon</summary>
        OpenIcon = 0x000000002,
        /// <summary>get shell size icon</summary>
        ShellIconSize = 0x000000004,
        /// <summary>pszPath is a pidl</summary>
        PIDL = 0x000000008,
        /// <summary>use passed dwFileAttribute</summary>
        UseFileAttributes = 0x000000010,
        /// <summary>apply the appropriate overlays</summary>
        AddOverlays = 0x000000020,
        /// <summary>Get the index of the overlay in the upper 8 bits of the iIcon</summary>
        OverlayIndex = 0x000000040,
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct SHFILEINFO
    {
        public SHFILEINFO(bool b)
        {
            hIcon = IntPtr.Zero;
            iIcon = 0;
            dwAttributes = 0;
            szDisplayName = "";
            szTypeName = "";
        }
        public IntPtr hIcon;
        public int iIcon;
        public uint dwAttributes;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
        public string szDisplayName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_TYPE)]
        public string szTypeName;
    };

    [DllImport("shell32.dll", CharSet = CharSet.Auto)]
    public static extern int SHGetFileInfo(
      string pszPath,
      int dwFileAttributes,
      out SHFILEINFO psfi,
      uint cbfileInfo,
      SHGFI uFlags);

    [DllImport("user32.dll", SetLastError = true)]
    public static extern bool DestroyIcon(IntPtr hIcon);
}