#region

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Runtime.InteropServices;
using Microsoft.Win32;

#endregion

namespace CSFrameworkV5.Common
{
    /// <summary>
    ///     图标工具
    /// </summary>
    public class IconTool
    {
        /// <summary>
        ///     数组转换为图像
        /// </summary>
        /// <param name="bs"></param>
        /// <returns></returns>
        public static Image ByteToImage(byte[] bs)
        {
            var ms = new MemoryStream(bs);
            var bmp = new Bitmap(ms);
            ms.Close();
            return bmp;
        }

        /// <summary>
        ///     获取文件的ICO图标
        /// </summary>
        /// <param name="fileType">文件类型(*.exe,*.dll)</param>
        /// <param name="large">大图标</param>
        /// <param name="small">返回小图标</param>
        public static void CreateFileIcon(string fileType, out Icon large,
            out Icon small)
        {
            string des;

            if (fileType.Trim() == "") //预设图标
            {
                GetDefaultIcon(out large, out small);
            }
            else if (fileType.ToUpper() == ".EXE") //应用程序图标单独获取
            {
                var l = IntPtr.Zero;
                var s = IntPtr.Zero;

                ExtractIconExW(
                    Path.Combine(Environment.SystemDirectory, "shell32.dll"), 2,
                    ref l, ref s, 1);

                large = Icon.FromHandle(l);
                small = Icon.FromHandle(s);
            }
            else //其它类型的图标
            {
                GetExtsIconAndDescription(fileType, out large, out small,
                    out des);
            }

            if (large == null || small == null) //无法获取图标,预设图标
                GetDefaultIcon(out large, out small);
        }

        /// Return Type: UINT->unsigned int   
        /// lpszFile: LPCWSTR->WCHAR*   
        /// nIconIndex: int   
        /// phiconLarge: HICON*   
        /// phiconSmall: HICON*   
        /// nIcons: UINT->unsigned int
        [DllImportAttribute("shell32.dll", EntryPoint = "ExtractIconExW",
            CallingConvention = CallingConvention.StdCall)]
        public static extern uint ExtractIconExW(
            [InAttribute] [MarshalAsAttribute(UnmanagedType.LPWStr)]
            string lpszFile, int nIconIndex,
            ref IntPtr phiconLarge, ref IntPtr phiconSmall, uint nIcons);

        /// <summary>
        ///     获取缺省图标
        /// </summary>
        /// <param name="largeIcon"></param>
        /// <param name="smallIcon"></param>
        public static void GetDefaultIcon(out Icon largeIcon,
            out Icon smallIcon)
        {
            largeIcon = smallIcon = null;
            var phiconLarge = new IntPtr();
            var phiconSmall = new IntPtr();
            ExtractIconExW(
                Path.Combine(Environment.SystemDirectory, "shell32.dll"), 0,
                ref phiconLarge,
                ref phiconSmall, 1);
            if (phiconLarge.ToInt32() > 0)
                largeIcon = Icon.FromHandle(phiconLarge);

            if (phiconSmall.ToInt32() > 0)
                smallIcon = Icon.FromHandle(phiconSmall);
        }

        /// <summary>
        ///     通过扩展名得到图标和描述
        /// </summary>
        /// <param name="ext">扩展名</param>
        /// <param name="LargeIcon">得到大图标</param>
        /// <param name="smallIcon">得到小图标</param>
        public static void GetExtsIconAndDescription(string ext,
            out Icon largeIcon, out Icon smallIcon,
            out string description)
        {
            //默认值
            largeIcon = null;
            smallIcon = null;
            description = "";

            if (string.IsNullOrWhiteSpace(ext)) return;

            if (ext.Length > 4) return; //控制文件扩展名长度4位,//防止注册表操纵 .jpg/.pdf

            var extsubkey =
                Registry.ClassesRoot.OpenSubKey(ext); //从注册表中读取扩展名相应的子键   

            if (extsubkey != null)
            {
                var extdefaultvalue =
                    extsubkey.GetValue(null).ToStringEx(); //取出扩展名对应的文件类型名称   
                var typesubkey =
                    Registry.ClassesRoot
                        .OpenSubKey(extdefaultvalue); //从注册表中读取文件类型名称的相应子键   
                if (typesubkey != null)
                {
                    description =
                        typesubkey.GetValue(null).ToStringEx(); //得到类型描述字符串   
                    var defaulticonsubkey =
                        typesubkey.OpenSubKey("DefaultIcon"); //取默认图标子键   
                    if (defaulticonsubkey != null)
                    {
                        //得到图标来源字符串   
                        var defaulticon = defaulticonsubkey.GetValue(null)
                            .ToStringEx(); //取出默认图标来源字符串   
                        var iconstringArray = defaulticon.Split(',');
                        var nIconIndex = 0;
                        if (iconstringArray.Length > 1)
                            int.TryParse(iconstringArray[1], out nIconIndex);

                        //得到图标   
                        var phiconLarge = new IntPtr();
                        var phiconSmall = new IntPtr();
                        ExtractIconExW(iconstringArray[0].Trim('"'), nIconIndex,
                            ref phiconLarge, ref phiconSmall, 1);
                        if (phiconLarge.ToInt32() > 0)
                            largeIcon = Icon.FromHandle(phiconLarge);

                        if (phiconSmall.ToInt32() > 0)
                            smallIcon = Icon.FromHandle(phiconSmall);
                    }
                }
            }
        }

        /// <summary>
        ///     图像转换为数组
        /// </summary>
        /// <param name="image"></param>
        /// <returns></returns>
        public static byte[] ImageToByte(Image image)
        {
            var ms = new MemoryStream();
            image.Save(ms, ImageFormat.Bmp);
            var bs = ms.ToArray();
            ms.Close();
            return bs;
        }
    }

    /// <summary>
    ///     图标句柄
    /// </summary>
    [StructLayoutAttribute(LayoutKind.Sequential)]
    public struct HICON__
    {
        public int unused;
    }
}