我发现dumpsys 活动最近"的 #0 条目给出了当前显示的活动......至少在我的 root 棉花糖设备上.这给了我我需要的东西.

I discovered that the #0 entry of "dumpsys activity recents" gives the currently displayed activity ... at least on my rooted Marshmallow device. This gives me what I need.