继续学习Android,我读了以下内容:
Question: Does the user have a choice to kill the application
unless we put a menu option in to kill it? If no such option exists,
how does the user terminate the application?
Answer: (Romain Guy): The user doesn't, the system handles this automatically. That's what the activity lifecycle (especially onPause/onStop/onDestroy) is for. No matter what you do, do not put a "quit" or "exit" application button. It is useless with Android's application model. This is also contrary to how core applications work.
呵呵,我在Android世界里每走一步都会遇到一些问题=(
显然,你不能在Android中退出应用程序(但Android系统可以随时完全销毁你的应用程序)。这是怎么回事?我开始认为这是不可能写一个应用程序的功能作为“正常的应用程序”-用户可以退出应用程序时,他/她决定这么做。这不应该依靠操作系统来完成。
我正在尝试创建的应用程序不是Android市场的应用程序。它不是一个被大众“广泛使用”的应用程序,它是一个将在非常狭窄的商业领域使用的商业应用程序。
我其实很期待为Android平台开发,因为它解决了Windows Mobile和。net中存在的许多问题。然而,上周对我来说有点令人失望……我希望我不必放弃Android,但它现在看起来不太好=(
有办法让我真的退出应用程序吗?
我会考虑阅读Addison-Wesley出版的“Android Wireless Application Development”。我刚刚完成它,它是非常彻底的。
看来你对Android平台有一些基本的误解。一开始我也对Android应用程序的生命周期感到有点沮丧,但在更深入地了解后,我开始真正享受这种方法。这本书将回答你所有的问题,甚至更多。这确实是我为Android新开发者找到的最好的资源。
Also, I think you need to let go of a line-for-line port of the existing app. In order to port your application to the Android platform, some of the application design is going to change. The application-lifecycle used is necessary as mobile devices have very limited resources relative to desktop systems and allows Android devices to run several applications in an orderly and resource-aware fashion. Do some more in depth study of the platform, and I think you will realize that what you are wanting to do is entirely feasible. Best of luck.
顺便说一下,我与艾迪生-卫斯理或与这本书有关的任何个人或组织都没有任何关系。重读了我的帖子后,我觉得我有点像个迷弟。我真的非常非常喜欢它,而且发现它非常有帮助。:)
这场争论可以归结为一个古老的问题:究竟是开发人员最了解,还是用户最了解。所有人为因素领域的专业设计师每天都在与这个问题作斗争。
Ted指出,市场上下载最多的应用之一是“应用杀手”。当人们停止应用时,他们会获得额外的血清素。他们已经习惯了台式机/笔记本电脑。它能让事情快速发展。它能让处理器保持凉爽,风扇也不会打开。它耗电更少。
当你认为移动设备是一艘小得多的船时,你就会特别感激他们“抛弃你不再需要的东西”的动机。现在,Android的开发者们认为操作系统才是最清楚的,退出一个应用程序已经过时了。我全心全意地支持这一点。
然而,我也认为你不应该让用户感到沮丧,即使这种沮丧是出于他们自己的无知。因此,我认为有一个“退出”选项是很好的设计,即使它只是一个安慰剂按钮,只是关闭一个视图。
这很简单。只要遵循我要告诉你的这些指示:
比如你有多个活动,从一个活动到另一个活动。你可能会像这样使用intent:
Intent i1 = new Intent(this, AnotherActivity);
startActivity(i1)
你只需要添加finish();例如,从头到尾在每个活动上启动intent活动后,
Intent i1=new Intent(this, AnotherActivity);
startActivity(i1)
finish();
所以当你点击退出按钮时使用的是finish()或System.exit(0)必须完全关闭你的应用程序。
我同意泰德的观点。我明白退出应用程序不是
“Android方式”,但它似乎不应该被排除。在这里
您可能需要一个真正的应用程序出口(不是
只是活动):
The user might want some control over which app gets killed in the
case of low memory. If important app A is running in the background,
then you might like to exit app B when you are done with it so
that app A doesn't get killed by the operating system.
If your application has sensitive data cached in memory, you might
like to kill the app so that a virus/worm/rogue app can't get at it. I
know the security model is supposed to prevent that, but just in case...
If your application uses resources (like network, CPU, sensors, etc.)
that could adversely affect the phone, then one way of ensuring that
those resources are freed up is to exit the application. I understand
that well-behaved apps should free up resources when they are not needed. But again, exiting the application seems like a reasonable way of ensuring that.