[Win32] [Powershell] Set Desktop Small Icon

desktopsmallicon.cmd

@setlocal enabledelayedexpansion & set "ARGS=%*" & powershell -nop -ex Bypass -c "Add-Type (gc '%~dpf0'|select -Skip 1|Out-String); exit [Program]::Main();" & exit /b !ERRORLEVEL!

using System;
using System.Runtime.InteropServices;

public static class Program {
    [DllImport("user32.dll")]
    static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);

    [DllImport("user32.dll", EntryPoint="GetWindowLongPtr")]
    static extern IntPtr GetWindowLongPtr(IntPtr hWnd, int nIndex);

    [DllImport("user32.dll", EntryPoint="SetWindowLongPtr")]
    private static extern IntPtr SetWindowLongPtr64(IntPtr hWnd, int nIndex, IntPtr dwNewLong);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    private static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, IntPtr lParam);

    const int GWL_STYLE     = -16;
    const int LVS_TYPEMASK  = 0x0003;
    const int LVS_SMALLICON = 0x0002;
    const string WC_LISTVIEW = "SysListView32";

    const int WM_MOUSEWHEEL = 0x020A;
    const int WHEEL_DELTA = 120;
    const int MK_CONTROL = 8;
    const int CtrlWheelDown = ((-WHEEL_DELTA) << 16) | MK_CONTROL;

    public static int Main() {
        IntPtr h = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "Progman", "Program Manager");
        h = FindWindowEx(h, IntPtr.Zero, "SHELLDLL_DefView", null);
        h = FindWindowEx(h, IntPtr.Zero, WC_LISTVIEW, null);

        var s = (long) GetWindowLongPtr(h, GWL_STYLE);
        s &= ~LVS_TYPEMASK;
        s |= LVS_SMALLICON;
        SetWindowLongPtr64(h, GWL_STYLE, (IntPtr) s);

        for (int i = 0; i < 16; ++i) {
            SendMessage(h, WM_MOUSEWHEEL, CtrlWheelDown, IntPtr.Zero);
        }

        return 0; // exit code => !ERRORLEVEL!
    }
}

Very cool thanks !