Get the icon for a given extension
Use the GetFileIcon method from this CodeProject article from Paul Ingles and pass .ext as the name parameter.
The GetFileIcon method is a wrapper around the native SHGetFileInfo and copied here for illustration:
public static System.Drawing.Icon GetFileIcon(string name, IconSize size,
bool linkOverlay)
{
Shell32.SHFILEINFO shfi = new Shell32.SHFILEINFO();
uint flags = Shell32.SHGFI_ICON | Shell32.SHGFI_USEFILEATTRIBUTES;
if (true == linkOverlay) flags += Shell32.SHGFI_LINKOVERLAY;
/* Check the size specified for return. */
if (IconSize.Small == size)
{
flags += Shell32.SHGFI_SMALLICON ; // include the small icon flag
}
else
{
flags += Shell32.SHGFI_LARGEICON ; // include the large icon flag
}
Shell32.SHGetFileInfo( name,
Shell32.FILE_ATTRIBUTE_NORMAL,
ref shfi,
(uint) System.Runtime.InteropServices.Marshal.SizeOf(shfi),
flags );
// Copy (clone) the returned icon to a new object, thus allowing us
// to call DestroyIcon immediately
System.Drawing.Icon icon = (System.Drawing.Icon)
System.Drawing.Icon.FromHandle(shfi.hIcon).Clone();
User32.DestroyIcon( shfi.hIcon ); // Cleanup
return icon;
}
Below code is also based on Paul Ingles solution, but:
- Usable with WPF (
ImageSourceinstead ofIcon) - Has simple caching
- Removed all stuff related to directories (I have only files in my case)
- Refactored using R# tips and wrapped with a single-class simple API
I've tested it on Windows 7 and Windows XP SP3, it works as expected with any string as a fileName.
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Media.Imaging;
/// <summary>
/// Internals are mostly from here: http://www.codeproject.com/Articles/2532/Obtaining-and-managing-file-and-folder-icons-using
/// Caches all results.
/// </summary>
public static class IconManager
{
private static readonly Dictionary<string, ImageSource> _smallIconCache = new Dictionary<string, ImageSource>();
private static readonly Dictionary<string, ImageSource> _largeIconCache = new Dictionary<string, ImageSource>();
/// <summary>
/// Get an icon for a given filename
/// </summary>
/// <param name="fileName">any filename</param>
/// <param name="large">16x16 or 32x32 icon</param>
/// <returns>null if path is null, otherwise - an icon</returns>
public static ImageSource FindIconForFilename(string fileName, bool large)
{
var extension = Path.GetExtension(fileName);
if (extension == null)
return null;
var cache = large ? _largeIconCache : _smallIconCache;
ImageSource icon;
if (cache.TryGetValue(extension, out icon))
return icon;
icon = IconReader.GetFileIcon(fileName, large ? IconReader.IconSize.Large : IconReader.IconSize.Small, false).ToImageSource();
cache.Add(extension, icon);
return icon;
}
/// <summary>
/// http://stackoverflow.com/a/6580799/1943849
/// </summary>
static ImageSource ToImageSource(this Icon icon)
{
var imageSource = Imaging.CreateBitmapSourceFromHIcon(
icon.Handle,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
return imageSource;
}
/// <summary>
/// Provides static methods to read system icons for both folders and files.
/// </summary>
/// <example>
/// <code>IconReader.GetFileIcon("c:\\general.xls");</code>
/// </example>
static class IconReader
{
/// <summary>
/// Options to specify the size of icons to return.
/// </summary>
public enum IconSize
{
/// <summary>
/// Specify large icon - 32 pixels by 32 pixels.
/// </summary>
Large = 0,
/// <summary>
/// Specify small icon - 16 pixels by 16 pixels.
/// </summary>
Small = 1
}
/// <summary>
/// Returns an icon for a given file - indicated by the name parameter.
/// </summary>
/// <param name="name">Pathname for file.</param>
/// <param name="size">Large or small</param>
/// <param name="linkOverlay">Whether to include the link icon</param>
/// <returns>System.Drawing.Icon</returns>
public static Icon GetFileIcon(string name, IconSize size, bool linkOverlay)
{
var shfi = new Shell32.Shfileinfo();
var flags = Shell32.ShgfiIcon | Shell32.ShgfiUsefileattributes;
if (linkOverlay) flags += Shell32.ShgfiLinkoverlay;
/* Check the size specified for return. */
if (IconSize.Small == size)
flags += Shell32.ShgfiSmallicon;
else
flags += Shell32.ShgfiLargeicon;
Shell32.SHGetFileInfo(name,
Shell32.FileAttributeNormal,
ref shfi,
(uint)Marshal.SizeOf(shfi),
flags);
// Copy (clone) the returned icon to a new object, thus allowing us to clean-up properly
var icon = (Icon)Icon.FromHandle(shfi.hIcon).Clone();
User32.DestroyIcon(shfi.hIcon); // Cleanup
return icon;
}
}
/// <summary>
/// Wraps necessary Shell32.dll structures and functions required to retrieve Icon Handles using SHGetFileInfo. Code
/// courtesy of MSDN Cold Rooster Consulting case study.
/// </summary>
static class Shell32
{
private const int MaxPath = 256;
[StructLayout(LayoutKind.Sequential)]
public struct Shfileinfo
{
private const int Namesize = 80;
public readonly IntPtr hIcon;
private readonly int iIcon;
private readonly uint dwAttributes;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = MaxPath)]
private readonly string szDisplayName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = Namesize)]
private readonly string szTypeName;
};
public const uint ShgfiIcon = 0x000000100; // get icon
public const uint ShgfiLinkoverlay = 0x000008000; // put a link overlay on icon
public const uint ShgfiLargeicon = 0x000000000; // get large icon
public const uint ShgfiSmallicon = 0x000000001; // get small icon
public const uint ShgfiUsefileattributes = 0x000000010; // use passed dwFileAttribute
public const uint FileAttributeNormal = 0x00000080;
[DllImport("Shell32.dll")]
public static extern IntPtr SHGetFileInfo(
string pszPath,
uint dwFileAttributes,
ref Shfileinfo psfi,
uint cbFileInfo,
uint uFlags
);
}
/// <summary>
/// Wraps necessary functions imported from User32.dll. Code courtesy of MSDN Cold Rooster Consulting example.
/// </summary>
static class User32
{
/// <summary>
/// Provides access to function required to delete handle. This method is used internally
/// and is not required to be called separately.
/// </summary>
/// <param name="hIcon">Pointer to icon handle.</param>
/// <returns>N/A</returns>
[DllImport("User32.dll")]
public static extern int DestroyIcon(IntPtr hIcon);
}
}
It can be done much simpler:
System.Drawing.Icon.ExtractAssociatedIcon("<fullPath>");
Important note: it will throw an exception if the file does not exists so worth to add validation.