#Requires AutoHotkey v2.0#z::
{
ToolTip   "Notepad窗口所在显示屏是：" GetMonitor()
}
GetMonitor()
{CoordMode("Mouse", "Screen"); MouseGetPos  &mx, &myWinGetPos &mx, &my,,,"ahk_class Notepad"monitorsCount:=SysGet(80)Loop monitorsCount{; SysGet, monitor, Monitor, %A_Index%ActualN := MonitorGet(A_Index, &monitorLeft, &monitorTop, &monitorRight, &monitorBottom)if (monitorLeft <= mx && mx <= monitorRight && monitorTop <= my && my <= monitorBottom){Return A_Index}}Return 1	
}

运行方环境 AutoHotkey V2

验证步骤：1、运行记事本，拖到某个屏幕上。

                  2、按热键：win+z，查看Tooltip输出情况。

运行效果：