Toggle hide desktop icons, see https://rammichael.com/7-taskbar-tweaker/comment-page-48#comment-12232

toggle_hide_desktop_icons.c

#include <windows.h>

BOOL CALLBACK WndEnumProc(HWND hWnd, LPARAM lParam)
{
	WCHAR szClassName[16];
	if (GetClassName(hWnd, szClassName, _countof(szClassName)) == 0)
		return TRUE;

	if (lstrcmp(szClassName, L"WorkerW") != 0)
		return TRUE;

	HWND hChildWnd = FindWindowEx(hWnd, NULL, L"SHELLDLL_DefView", NULL);
	if (!hChildWnd)
		return TRUE;

	*(HWND *)lParam = hChildWnd;
	return FALSE;
}

int main()
{
	HWND hParentWnd = FindWindow(L"Progman", NULL);
	if (!hParentWnd)
		return 1;

	HWND hChildWnd = FindWindowEx(hParentWnd, NULL, L"SHELLDLL_DefView", NULL);
	if (!hChildWnd)
	{
		DWORD dwThreadId = GetWindowThreadProcessId(hParentWnd, NULL);
		EnumThreadWindows(dwThreadId, WndEnumProc, (LPARAM)&hChildWnd);
	}

	if (!hChildWnd)
		return 2;

	PostMessage(hChildWnd, WM_COMMAND, 0x7402, 0);
	return 0;
}

Binary: ToggleHideDesktopIcons.exe.