using System.Runtime.InteropServices;

// Constants that we need in the function call

private const int SHGFI_ICON = 0x100;

private const int SHGFI_SMALLICON = 0x1;

private const int SHGFI_LARGEICON = 0x0;

// This structure will contain information about the file

public struct SHFILEINFO

{

    // Handle to the icon representing the file

    public IntPtr hIcon;

    // Index of the icon within the image list

    public int iIcon;

    // Various attributes of the file

    public uint dwAttributes;

    // Path to the file

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]

    public string szDisplayName;

    // File type

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

    public string szTypeName;

};

// The signature of SHGetFileInfo (located in Shell32.dll)

[DllImport("Shell32.dll")]

public static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, int cbFileInfo, uint uFlags);

private void btnExtract_Click(object sender, EventArgs e)

{

    // Will store a handle to the small icon

    IntPtr hImgSmall;

    // Will store a handle to the large icon

    IntPtr hImgLarge;

    SHFILEINFO shinfo = new SHFILEINFO();

    // Open the file that we wish to extract the icon from

    if(openFile.ShowDialog() == DialogResult.OK)

    {

        // Store the file name

        string FileName = openFile.FileName;

        // Sore the icon in this myIcon object

        System.Drawing.Icon myIcon;

        // Get a handle to the small icon

        hImgSmall = SHGetFileInfo(FileName, 0, ref shinfo, Marshal.SizeOf(shinfo), SHGFI_ICON | SHGFI_SMALLICON);

        // Get the small icon from the handle

        myIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon);

        // Display the small icon

        picIconSmall.Image = myIcon.ToBitmap();

        // Get a handle to the large icon

        hImgLarge = SHGetFileInfo(FileName, 0, ref shinfo, Marshal.SizeOf(shinfo), SHGFI_ICON | SHGFI_LARGEICON);

        // Get the large icon from the handle

        myIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon);

        // Display the large icon

        picIconLarge.Image = myIcon.ToBitmap();

    }

}

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Runtime.InteropServices;

namespace ExtractIcon

{

    public partial class Form1 : Form

    {

        // Constants that we need in the function call

        private const int SHGFI_ICON = 0x100;

        private const int SHGFI_SMALLICON = 0x1;

        private const int SHGFI_LARGEICON = 0x0;

        // This structure will contain information about the file

        public struct SHFILEINFO

        {

            // Handle to the icon representing the file

            public IntPtr hIcon;

            // Index of the icon within the image list

            public int iIcon;

            // Various attributes of the file

            public uint dwAttributes;

            // Path to the file

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]

            public string szDisplayName;

            // File type

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

            public string szTypeName;

        };

        // The signature of SHGetFileInfo (located in Shell32.dll)

        [DllImport("Shell32.dll")]

        public static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, int cbFileInfo, uint uFlags);

        public Form1()

        {

            InitializeComponent();

        }

        private void btnExtract_Click(object sender, EventArgs e)

        {

            // Will store a handle to the small icon

            IntPtr hImgSmall;

            // Will store a handle to the large icon

            IntPtr hImgLarge;

            SHFILEINFO shinfo = new SHFILEINFO();

            // Open the file that we wish to extract the icon from

            if(openFile.ShowDialog() == DialogResult.OK)

            {

                // Store the file name

                string FileName = openFile.FileName;

                // Sore the icon in this myIcon object

                System.Drawing.Icon myIcon;

                // Get a handle to the small icon

                hImgSmall = SHGetFileInfo(FileName, 0, ref shinfo, Marshal.SizeOf(shinfo), SHGFI_ICON | SHGFI_SMALLICON);

                // Get the small icon from the handle

                myIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon);

                // Display the small icon

                picIconSmall.Image = myIcon.ToBitmap();

                // Get a handle to the large icon

                hImgLarge = SHGetFileInfo(FileName, 0, ref shinfo, Marshal.SizeOf(shinfo), SHGFI_ICON | SHGFI_LARGEICON);

                // Get the large icon from the handle

                myIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon);

                // Display the large icon

                picIconLarge.Image = myIcon.ToBitmap();

            }

        }

    }

}