C#获取系统文件及文件夹图标

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.IO;
using System.Drawing;

class GetSysicon
{
/// <summary>
/// 获得指定文件图标句柄
/// </summary>
/// <param name="path">指定的文件名</param>
/// <param name="fileattribute">文件属性</param>
/// <param name="?">返回的文件信息</param>
/// <param name="SizeFileInfo">sfinfo的比特值</param>
/// <param name="flag">指明要返回的文件信息标识符</param>
/// <returns>文件的图标句柄</returns>
[DllImport("shell32.dll", EntryPoint = "SHGetFileInfo")]
public static extern IntPtr SHGetFileInfo(string path, uint fileattribute, ref SHFILEINFO sfinfo
, uint SizeFileInfo, uint flag);

/// <summary>
/// 图标结构
/// </summary>
[StructLayout(LayoutKind.Sequential)]//自定义类型
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 aattributes;//文件的属性值
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]//MarshalAs只是如何在托管代码和非托管代码间传送数据
public string displayname;//文件的显示名
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
public string typename;//文件的类型
}

/// <summary>
/// 清除图标
/// </summary>
/// <param name="hIcon">图标句柄</param>
/// <returns>返回非零表示成功，零表示失败</returns>
[DllImport("user32.dll", EntryPoint = "DestroyIcon")]
public static extern int DestroyIcon(IntPtr hIcon);

/// <summary>
/// 获取指定路径的系统图标
/// </summary>
/// <param name="path">路径</param>
/// <param name="imglist">Imagelist对象保存图标</param>
/// <param name="flag">表示是否为获取文件夹图标，true为获取文件夹图标，false为获取文件图标</param>
public static void GetSysIcon(string path, ImageList imglist, bool flag)
{
SHFILEINFO shfi = new SHFILEINFO();
if (flag)
{
DirectoryInfo dir = new DirectoryInfo(path);
if (dir.Name == "RECYCLER" || dir.Name == "RECYCLED" || dir.Name == "Recycled" ||
dir.Name == "System Volume Information")//windows系统文件夹
{ }
else
{
SHGetFileInfo(path, (uint)0x80, ref shfi,
(uint)Marshal.SizeOf(shfi),//Marshal.SizeOf返回对象的非托管大小
(uint)(0x100 | 0x400));//取得icon和typename
imglist.Images.Add(dir.Name, (Icon)Icon.FromHandle(shfi.hIcon).Clone());
DestroyIcon(shfi.hIcon);
}
}
else
{
FileInfo file = new FileInfo(path);
string exten = Path.GetExtension(path).Substring(1, Path.GetExtension(path).Length-1).ToLower();//获取路径文件的扩展名，并去掉.
if (exten=="sys"||exten=="ini"||exten=="bin"||exten=="log"||
exten == "com" || exten == "bat" || exten == "db")
{}
else
{
SHGetFileInfo(path,(uint)0x80,ref shfi,
(uint)Marshal.SizeOf(shfi),(uint)(0x100|0x400));
imglist.Images.Add(file.Name, (Icon)Icon.FromHandle(shfi.hIcon).Clone());
DestroyIcon(shfi.hIcon);
}
}
}
}