using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.IO;

using System.Linq;

using System.Runtime.InteropServices;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace FileExplorer

{

    /// <summary>

    /// 系统Icon

    /// 1、Get()  获取指定索引对应的系统icon

    /// 2、Save() 保存所有系统图像

    /// 3、Show() 显示所有系统Icon图像

    /// </summary>

    public partial class SystemIcon : Form

    {

        public SystemIcon()

        {

            InitializeComponent();

            Show(this);

            Save();

        }

        /// <summary>

        /// 在form上显示所有系统icon图像

        /// </summary>

        public static void Show(Form form)

        {

            LoadSystemIcon();

            FlowLayoutPanel flowLayout = new FlowLayoutPanel();

            flowLayout.Dock = System.Windows.Forms.DockStyle.Fill;

            flowLayout.AutoScroll = true;

            for (int i = 0; i < SystemIconList.Count; i++)

            {

                PictureBox pic = new PictureBox();

                pic.Size = new System.Drawing.Size(32, 32);

                flowLayout.Controls.Add(pic);

                Bitmap p = SystemIconList[i].ToBitmap();

                pic.Image = p;

            }

            form.Controls.Add(flowLayout);

        }

        /// <summary>

        /// 保存所有系统图像

        /// </summary>

        public static void Save()

        {

            LoadSystemIcon();

            for (int i = 0; i < SystemIconList.Count; i++)

            {

                Bitmap p = SystemIconList[i].ToBitmap();

                // 保存图像

                string path = AppDomain.CurrentDomain.BaseDirectory + "系统图标\\";

                string filepath = path + (i + ".png");

                if (!Directory.Exists(path)) Directory.CreateDirectory(path);

                if (!File.Exists(filepath)) p.Save(filepath);

            }

        }

        /// <summary>

        /// 获取指定索引对应的系统icon

        /// </summary>

        public static Icon Get(int index)

        {

            LoadSystemIcon();

            return index < SystemIconList.Count ? SystemIconList[index] : null;

        }

        private static List<Icon> SystemIconList = new List<Icon>(); // 记录系统图标

        //[DllImport("user32.dll", CharSet = CharSet.Auto)]

        //private static extern bool MessageBeep(uint type);

        [DllImport("Shell32.dll")]

        public extern static int ExtractIconEx(string libName, int iconIndex, IntPtr[] largeIcon, IntPtr[] smallIcon, int nIcons);

        private static IntPtr[] largeIcon;

        private static IntPtr[] smallIcon;

        /// <summary>

        /// 获取所有系统icon图像

        /// </summary>

        private static void LoadSystemIcon()

        {

            if (SystemIconList.Count > 0) return;

            largeIcon = new IntPtr[1000];

            smallIcon = new IntPtr[1000];

            ExtractIconEx("shell32.dll", 0, largeIcon, smallIcon, 1000);

            SystemIconList.Clear();

            for (int i = 0; i < largeIcon.Length; i++)

            {

                try

                {

                    Icon ic = Icon.FromHandle(largeIcon[i]);

                    SystemIconList.Add(ic);

                }

                catch (Exception ex)

                {

                    break;

                }

            }

        }

        //private void LoadSystemIcon()

        //{

        //    largeIcon = new IntPtr[1000];

        //    smallIcon = new IntPtr[1000];

        //    ExtractIconEx("shell32.dll", 0, largeIcon, smallIcon, 1000);

        //    FlowLayoutPanel flowLayout = new FlowLayoutPanel();

        //    flowLayout.Dock = System.Windows.Forms.DockStyle.Fill;

        //    flowLayout.AutoScroll = true;

        //    for (int i = 0; i < largeIcon.Length; i++)

        //    {

        //        try

        //        {

        //            PictureBox pic = new PictureBox();

        //            pic.Size = new System.Drawing.Size(32, 32);

        //            flowLayout.Controls.Add(pic);

        //            Icon ic = Icon.FromHandle(largeIcon[i]);

        //            SystemIcon.Add(ic);

        //            Bitmap p = ic.ToBitmap();

        //            pic.Image = p;

        //            // 保存图像

        //            string path = AppDomain.CurrentDomain.BaseDirectory + "系统图标\\";

        //            string filepath = path + (i + ".png");

        //            if (!Directory.Exists(path)) Directory.CreateDirectory(path);

        //            if (!File.Exists(filepath)) p.Save(filepath);

        //        }

        //        catch (Exception ex)

        //        {

        //            break;

        //        }

        //    }

        //    this.Controls.Add(flowLayout);

        //}

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.InteropServices;

using System.Windows.Forms;

using System.IO;

using System.Drawing;

using Microsoft.Win32;

namespace FileExplorer

{

    /// <summary>

    /// 获取指定文件的Icon图像getIcon()、getIcon2()

    /// </summary>

    class FileIcon

    {

        private const uint SHGFI_ICON = 0x100;

        private const uint SHGFI_LARGEICON = 0x0;  //大图标

        private const uint SHGFI_SMALLICON = 0x1;  //小图标

        [StructLayout(LayoutKind.Sequential)]

        public struct SHFILEINFO

        {

            public IntPtr hIcon;        //文件的图标句柄  

            public IntPtr iIcon;        //图标的系统索引号  

            public uint dwAttributes;   //文件的属性值  

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]

            public string szDisplayName;//文件的显示名  

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]

            public string szTypeName;   //文件的类型名

        };

        [DllImport("shell32.dll")]

        private static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, uint cbSizeFileInfo, uint uFlags);

        /// <summary>

        /// 获取文件FilePath对应的Icon

        /// </summary>

        public static Icon getIcon(string FilePath)

        {

            SHFILEINFO shinfo = new SHFILEINFO();

            //FileInfo info = new FileInfo(FileName);

            //大图标

            SHGetFileInfo(FilePath, 0, ref shinfo, (uint)Marshal.SizeOf(shinfo), SHGFI_ICON | SHGFI_LARGEICON);

            Icon largeIcon = Icon.FromHandle(shinfo.hIcon);

            //Icon.ExtractAssociatedIcon(FileName);

            return largeIcon;

        }

        /// <summary>

        /// 获取文件FilePath对应的Icon

        /// </summary>

        public static Icon getIcon2(string FilePath)

        {

            return Icon.ExtractAssociatedIcon(FilePath);

        }

    }

}