Android 怎么退出整个应用程序

Android 怎么退出整个应用程序

1.后面添加了一个菜单返回功能键，这个方法也只能用system.exit(0)来关闭当前活动的Activity，附代码：public boolean onCreateOptionsMenu(Menu menu){super.onCreateOptionsMenu(menu);MenuItem item = menu.add(Menu.NONE, Menu.NONE, Menu.NONE, "Exit");item.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener(){public boolean onMenuItemClick(MenuItem item){System.exit(0);return true;}});return true;}2.这样太不方便，每次退出界面之后应用程序还在运行，网上提供了几种方法，将下面SysApplication这个类复制到工程里面，然后在每个Acitivity的oncreate方法里面通过SysApplication.getInstance().addActivity(this); 添加当前Acitivity到ancivitylist里面去，最后在想退出的时候调用SysApplication.getInstance().exit();可直接关闭所有的Acitivity并退出应用程序。附代码：import java.util.LinkedList; import java.util.List; import android.app.Activity; import android.app.AlertDialog; import android.app.Application; import android.content.DialogInterface; import android.content.Intent; public class SysApplication extends Application { private List mList = new LinkedList(); private static SysApplication instance; private SysApplication() { } public synchronized static SysApplication getInstance() { if (null == instance) { instance = new SysApplication(); } return instance; } // add Activity public void addActivity(Activity activity) { mList.add(activity); } public void exit() { try { for (Activity activity : mList) { if (activity != null) activity.finish(); } } catch (Exception e) { e.printStackTrace(); } finally { System.exit(0); } } public void onLowMemory() { super.onLowMemory(); System.gc(); } }3.在应用程序里面 的activity的oncreate里面添加SysApplication.getInstance().addActivity(this)如：public void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.main);SysApplication.getInstance().addActivity(this); }