C# 获取系统文件图标

[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;
}

/// <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);

public enum SHGFI
{
SHGFI_ICON = 0x100,
SHGFI_LARGEICON = 0x0,
SHGFI_USEFILEATTRIBUTES = 0x10
}

/// <summary>
/// 获取文件图标 zgke@sina.com qq:116149
/// </summary>
/// <param name="p_Path">文件全路径</param>
/// <returns>图标</returns>
public static 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  zgke@sina.com qq:116149
/// </summary>
/// <returns>图标</returns>
public static 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;
}