获取文件图标

参考来源:http://bg5sbk.cnblogs.com/archive/2005/12/18/GetFileInfo.html

获取文件和文件夹的图标

using System;
using System.Runtime.InteropServices;
using System.Drawing;

namespace ThunderStarter
{
    public class CGetFileIcon
    {
        /// <summary>
        /// 通过路径获取图标
        /// </summary>
        /// <param name="path">文件或文件夹路径</param>
        /// <returns>获取的图标</returns>
        public static Icon GetLargeIcon(string path)
        {
            return GetIcon(path, FileInfo.GetFileInfoFlags.SHGFI_LARGEICON);
        }
        public static Icon GetSmallIcon(string path)
        {
            return GetIcon(path, FileInfo.GetFileInfoFlags.SHGFI_SMALLICON);
        }
        private static Icon GetIcon(string path,FileInfo.GetFileInfoFlags type)
        {
            FileInfo.FileInfomation _info = new FileInfo.FileInfomation();
            FileInfo.GetFileInfo(path, 0, ref _info, Marshal.SizeOf(_info),
                (int)(FileInfo.GetFileInfoFlags.SHGFI_ICON | type));

            try
            {
                return Icon.FromHandle(_info.hIcon);
            }
            catch
            {
                return null;
            }
        }
    }
    
    /// <summary>
    /// 获取文件系统中对象的信息，例如：文件、文件夹、驱动器根目录
    /// </summary>
    public class FileInfo
    {
        [DllImport("shell32.dll", EntryPoint = "SHGetFileInfo")]
        public static extern int GetFileInfo(string pszPath, int dwFileAttributes, ref FileInfomation psfi, int cbFileInfo, int uFlags);

        private FileInfo() { }

        [StructLayout(LayoutKind.Sequential)]
        public struct FileInfomation
        {
            public IntPtr hIcon;
            public int iIcon;
            public int dwAttributes;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
            public string szDisplayName;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
            public string szTypeName;
        }

        public enum FileAttributeFlags : int
        {
            FILE_ATTRIBUTE_READONLY = 0x00000001,
            FILE_ATTRIBUTE_HIDDEN = 0x00000002,
            FILE_ATTRIBUTE_SYSTEM = 0x00000004,
            FILE_ATTRIBUTE_DIRECTORY = 0x00000010,
            FILE_ATTRIBUTE_ARCHIVE = 0x00000020,
            FILE_ATTRIBUTE_DEVICE = 0x00000040,
            FILE_ATTRIBUTE_NORMAL = 0x00000080,
            FILE_ATTRIBUTE_TEMPORARY = 0x00000100,
            FILE_ATTRIBUTE_SPARSE_FILE = 0x00000200,
            FILE_ATTRIBUTE_REPARSE_POINT = 0x00000400,
            FILE_ATTRIBUTE_COMPRESSED = 0x00000800,
            FILE_ATTRIBUTE_OFFLINE = 0x00001000,
            FILE_ATTRIBUTE_NOT_CONTENT_INDEXED = 0x00002000,
            FILE_ATTRIBUTE_ENCRYPTED = 0x00004000
        }

        public enum GetFileInfoFlags : int
        {
            SHGFI_ICON = 0x000000100,     // get icon
            SHGFI_DISPLAYNAME = 0x000000200,     // get display name
            SHGFI_TYPENAME = 0x000000400,     // get type name
            SHGFI_ATTRIBUTES = 0x000000800,     // get attributes
            SHGFI_ICONLOCATION = 0x000001000,     // get icon location
            SHGFI_EXETYPE = 0x000002000,     // return exe type
            SHGFI_SYSICONINDEX = 0x000004000,     // get system icon index
            SHGFI_LINKOVERLAY = 0x000008000,     // put a link overlay on icon
            SHGFI_SELECTED = 0x000010000,     // show icon in selected state
            SHGFI_ATTR_SPECIFIED = 0x000020000,     // get only specified attributes
            SHGFI_LARGEICON = 0x000000000,     // get large icon
            SHGFI_SMALLICON = 0x000000001,     // get small icon
            SHGFI_OPENICON = 0x000000002,     // get open icon
            SHGFI_SHELLICONSIZE = 0x000000004,     // get shell size icon
            SHGFI_PIDL = 0x000000008,     // pszPath is a pidl
            SHGFI_USEFILEATTRIBUTES = 0x000000010,     // use passed dwFileAttribute
            SHGFI_ADDOVERLAYS = 0x000000020,     // apply the appropriate overlays
            SHGFI_OVERLAYINDEX = 0x000000040     // Get the index of the overlay
        }
    }
}