Android上下文中的应用程序只是一堆模糊相关的活动，退出应用程序并没有多大意义。你可以finish()一个Activity, Activity栈中前一个Activity的视图就会被绘制出来。

Android上下文中的应用程序只是一堆模糊相关的活动，退出应用程序并没有多大意义。你可以finish()一个Activity, Activity栈中前一个Activity的视图就会被绘制出来。

不要把您的应用程序看作一个整体应用程序。它是一组UI屏幕，用户可以通过Android服务与你的“应用程序”和“功能”进行交互。

不知道你的神秘应用程序“做什么”并不重要。让我们假设它通过隧道进入某个超级安全的企业内部网，执行一些监控或交互，并保持登录状态，直到用户“退出应用程序”。因为您的IT部门命令它，所以用户必须非常清楚他们何时进入或退出内部网。因此你认为用户“退出”很重要。

这很简单。创建一个服务，在通知栏中放置一个持续通知，说“我在内部网中，或者我正在运行”。让该服务执行应用程序所需的所有功能。拥有绑定到该服务的活动，以允许用户访问与“应用程序”交互所需的UI部分。并有一个Android菜单->退出(或登出，或其他)按钮，告诉服务退出，然后关闭活动本身。

This is, for all intents and purposes exactly what you say you want. Done the Android way. Look at Google Talk or Google Maps Navigation for examples of this "exit" is possible mentality. The only difference is that pressing back button out of your activity might leave your UNIX process lying in wait just in case the user wants to revive your application. This is really no different than a modern operating system that caches recently accessed files in memory. After you quit your windows program, most likely resources that it needed are still in memory, waiting to be replaced by other resources as they are loaded now that they are no longer needed. Android is the same thing.

我真不明白你有什么问题。

如果你有10个，20个…有多个活动正在运行，你想要完成所有活动并退出系统。

在应用程序类或常量类中创建静态数组。

常量

public class Constants {

public static ArrayList<Activity> activities = new ArrayList<Activity>();

}

在此数组中添加当前活动引用

activity = MainActivity.this; Constants.activities.add(活动);

public class MainActivity extends Activity {

    private ImageView imageButton;
    private Activity activity;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        activity = MainActivity.this;
        Constants.activities.add(activity);

        imageButton = (ImageView) findViewById(R.id.camera);
        imageButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                // existing app.
                if (Constants.activities != null) {
                    for (int i = 0; i < Constants.activities.size(); i++) {
                        Activity s = Constants.activities.get(i);
                        s.finish();
                    }
                }
                //super.finish();
                finish();
                android.os.Process.killProcess(android.os.Process.myPid());
                System.exit(1);
            }
        });
    }
}

我认为关键是没有必要退出应用程序，除非你的软件有问题。Android会在用户不使用该应用且设备需要更多内存时退出该应用。如果你有一个需要在后台运行服务的应用程序，你可能需要一种方法来关闭服务。

For example, Google Listen continues to play podcast when the app is not visible. But there is always the pause button to turn the podcast off when the user is done with it. If I remember correctly, Listen, even puts a shortcut in the notification bar so you can always get to the pause button quickly. Another example is an app like a twitter app for instance which constantly polls a service on the internet. These types of apps should really allow the user to choose how often to poll the server, or whether even to poll in a background thread.

如果你需要在退出时运行的代码，你可以根据需要重写onPause()， onStop()或onDestroy()。 http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

博客文章“何时在Android应用程序中包含退出按钮”(提示:永远不要)解释得比我好得多。我希望每个Android开发者都读过这本书。

摘录:

In my experience what [the users] really want is: An unambiguous way to guarantee that an app will stop consuming resources (battery, CPU cycles, data transfer, etc.). Many users perceive that an exit button implements this requirement and ask for it to be added. Developers, looking to please their users, obligingly add one. Shortly thereafter they both fail. In most cases the exit button simply calls Activity.finish(). This is exactly equivalent to hitting the back button. Exactly. Services keep running and polling keeps happening. Users may think they've killed the app but they haven't, and soon they'll be even more annoyed. Exit behavior is now ambiguous. Should your exit button just close the Activity, or should it also stop all associated Services, Receivers, and Alarms? What should Back do? What happens if they hit Home instead? What happens if your app has a widget? Should the exit button stop that from updating too? The solution is to make the back button behave as you'd expect the exit button to. Better yet, simply stop consuming resources whenever the app isn't visible.

继续阅读完整的文章。