How to use SHGetStockIconInfo in Powershell? - powershell

Question

I'm trying to pull folder icons for a listview in a winform. I'm using [Drawing.Icon]::ExtractAssociatedIcon for file icons, but it doesn't work on folders.
I found this question here on stack which said to use SHGetStockIconInfo, but I can't wrap my head around how to load this function and use it in Powershell (I have no C programming experience). I managed to pull this from the linked question, but I'm stuck:
Add-Type -NameSpace WinAPI -Name DefaultIcons -MemberDefinition #'
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct SHSTOCKICONINFO {
public uint cbSize;
public IntPtr hIcon;
public int iSysIconIndex;
public int iIcon;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
public string szPath;
}
[DllImport("shell32.dll")]
public static extern int SHGetStockIconInfo(uint siid, uint uFlags, ref SHSTOCKICONINFO psii);
[DllImport("user32.dll")]
public static extern bool DestroyIcon(IntPtr handle);
private const uint SHSIID_FOLDER = 0x3;
private const uint SHGSI_ICON = 0x100;
private const uint SHGSI_LARGEICON = 0x0;
private const uint SHGSI_SMALLICON = 0x1;
'#
This runs without error, but that's as far as I can get and I don't fully understand what's going on.
I know I need to call the function SHGetStockIconInfo with three parameters:
uint to identify what icon I want
uint flag for the size of icon I want
a reference to a SHSTOCKICONINFO structure
The question I got all this from includes a GetStockIcon function definition, but I keep getting errors trying to include it saying The type or namespace name 'Icon' could not be found (are you missing a using directive or an assembly reference?)

Answer 1

With a few adjustments I got the code from that C# question to work under both PowerShell 5.1 and 7.2.6.
$refAsm = if( $PSVersionTable.PSVersion.Major -le 5 ) {'System.Drawing'} else {'System.Drawing.Common'}
Add-Type -ReferencedAssemblies $refAsm -TypeDefinition #'
using System;
using System.Runtime.InteropServices;
using System.Drawing;
public static class DefaultIcons
{
public static Icon GetStockIcon(uint type, uint size)
{
var info = new SHSTOCKICONINFO();
info.cbSize = (uint)Marshal.SizeOf(info);
SHGetStockIconInfo(type, SHGSI_ICON | size, ref info);
var icon = (Icon)Icon.FromHandle(info.hIcon).Clone(); // Get a copy that does not use the original handle
DestroyIcon(info.hIcon); // Clean up native icon to prevent resource leak
return icon;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct SHSTOCKICONINFO
{
public uint cbSize;
public IntPtr hIcon;
public int iSysIconIndex;
public int iIcon;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
public string szPath;
}
[DllImport("shell32.dll")]
public static extern int SHGetStockIconInfo(uint siid, uint uFlags, ref SHSTOCKICONINFO psii);
[DllImport("user32.dll")]
public static extern bool DestroyIcon(IntPtr handle);
public const uint SHSIID_FOLDER = 0x3;
public const uint SHGSI_ICON = 0x100;
public const uint SHGSI_LARGEICON = 0x0;
public const uint SHGSI_SMALLICON = 0x1;
}
'#
Use it like this:
$folderIconLarge = [DefaultIcons]::GetStockIcon( [DefaultIcons]::SHSIID_FOLDER, [DefaultIcons]::SHGSI_LARGEICON )
$folderIconSmall = [DefaultIcons]::GetStockIcon( [DefaultIcons]::SHSIID_FOLDER, [DefaultIcons]::SHGSI_SMALLICON )