封装：Windows系统文件图标

原文:封装：Windows系统文件图标

用途：用于获取文件系统默认图标

using System;





using System.Collections.Generic;





using System.Drawing;





using System.IO;





using System.Linq;





using System.Runtime.InteropServices;





using System.Text;





 





namespace HebianGu.ComLibModule.API





{





 





    /// <summary> 获取文件关联图标 </summary>





    public partial class IconHelper





    {





        /// <summary> 返回系统设置的图标 </summary>  





        /// <param name="pszPath">文件路径 如果为""  返回文件夹的</param>  





        /// <param name="dwFileAttributes">0</param>  





        /// <param name="psfi">结构体</param>  





        /// <param name="cbSizeFileInfo">结构体大小</param>  





        /// <param name="uFlags">枚举类型</param>  





        /// <returns>-1失败</returns>  





        [DllImport("shell32.dll")]





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





 





        /// <summary> 获取文件图标 </summary>  





        public Icon GetFileIcon(string p_Path)





        {





            SHFILEINFO _SHFILEINFO = new SHFILEINFO();





            IntPtr _IconIntPtr = SHGetFileInfo(p_Path, 0, ref _SHFILEINFO, (uint)Marshal.SizeOf(_SHFILEINFO), (uint)(SHGFI.SHGFI_ICON | SHGFI.SHGFI_LARGEICON | SHGFI.SHGFI_USEFILEATTRIBUTES));





            if (_IconIntPtr.Equals(IntPtr.Zero)) return null;





            Icon _Icon = System.Drawing.Icon.FromHandle(_SHFILEINFO.hIcon);





            return _Icon;





        }





 





        /// <summary> 获取文件夹图标 </summary>  





        public Icon GetDirectoryIcon()





        {





            SHFILEINFO _SHFILEINFO = new SHFILEINFO();





            IntPtr _IconIntPtr = SHGetFileInfo(@"", 0, ref _SHFILEINFO, (uint)Marshal.SizeOf(_SHFILEINFO), (uint)(SHGFI.SHGFI_ICON | SHGFI.SHGFI_LARGEICON));





            if (_IconIntPtr.Equals(IntPtr.Zero)) return null;





            Icon _Icon = System.Drawing.Icon.FromHandle(_SHFILEINFO.hIcon);





            return _Icon;





        }





 





        /// <summary> 获取系统图标 </summary>  





        public Icon GetSystemInfoIcon(string p_Path)





        {





            if (Path.HasExtension(p_Path))





            {





                try





                {





                    return Icon.ExtractAssociatedIcon(p_Path);





                }





                catch





                {





                    return null;





                }





          





            }





            else





            {





                return this.GetDirectoryIcon();





            }





        }





 





    }





 





    partial class IconHelper





    {





        #region - Start 单例模式 -





 





        /// <summary> 单例模式 </summary>





        private static IconHelper t = null;





 





        /// <summary> 多线程锁 </summary>





        private static object localLock = new object();





 





        /// <summary> 创建指定对象的单例实例 </summary>





        public static IconHelper Instance





        {





            get





            {





                if (t == null)





                {





                    lock (localLock)





                    {





                        if (t == null)





                            return t = new IconHelper();





                    }





                }





                return t;





            }





        }





        /// <summary> 禁止外部实例 </summary>





        private IconHelper()





        {





 





        }





        #endregion - 单例模式 End -





 





    }





 





    [StructLayout(LayoutKind.Sequential)]





    public struct SHFILEINFO





    {





        public IntPtr hIcon;





        public IntPtr iIcon;





        public uint dwAttributes;





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





        public string szDisplayName;





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





        public string szTypeName;





    }





 





 





    public enum SHGFI





    {





        SHGFI_ICON = 0x100,





        SHGFI_LARGEICON = 0x0,





        SHGFI_USEFILEATTRIBUTES = 0x10





    }





}

应用示例：

        /// <summary> 图片路径 </summary>





        public Icon ImagePath





        {





            get { return IconHelper.Instance.GetSystemInfoIcon(FilePath); }





        }