我们希望每个Activity上都有一个按钮,它会直接返回主菜单 – 即除了第一个活动之外,从堆栈中弹出所有活动.
我把按钮放在一个View中,我可以很容易地把它放在应用程序中的每个Activity上,但我无法弄清楚如何一举关闭几个Activity.
(如果可能的话,如果View可以计算出自己关闭多少个活动就好了 – 也就是检测它自己的Activity有多深.)
解决方法
从文档：
If set,and the activity being
launched is already running in the
current task,then instead of
launching a new instance of that
activity,all of the other activities
on top of it will be closed and this
Intent will be delivered to the (now
on top) old activity as a new Intent.For example,consider a task
consisting of the activities: A,B,C,
D. If D calls startActivity() with an
Intent that resolves to the component
of activity B,then C and D will be
finished and B receive the given
Intent,resulting in the stack now
being: A,B.The currently running instance of
activity B in the above example will
either receive the new intent you are
starting here in its onNewIntent()
method,or be itself finished and
restarted with the new intent. If it
has declared its launch mode to be
“multiple” (the default) and you have
not set FLAG_ACTIVITY_SINGLE_TOP in
the same intent,then it will be
finished and re-created; for all other
launch modes or if
FLAG_ACTIVITY_SINGLE_TOP is set then
this Intent will be delivered to the
current instance’s onNewIntent().This launch mode can also be used to good effect in conjunction with FLAG_ACTIVITY_NEW_TASK: if used to start the root activity of a task,it will bring any currently running instance of that task to the foreground,and then clear it to its root state. This is especially useful,for example,when launching an activity from the notification manager.
