Android 退出整个应用程序

“三步走”

1、建立一个JAVA类

import java.util.LinkedList;
import java.util.List;

import android.app.Activity;
import android.app.Application;

public class SysApplication extends Application {

 private List<Activity> mList = new LinkedList<Activity>();
 private static SysApplication instance;

 private SysApplication() {
 }

 public synchronized static SysApplication getInstance() {
  if (null == instance) {
   instance = new SysApplication();
  }
  return instance;
 }

 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();
 }

}
2、在每个界面onCreate()方法中添加此行
  SysApplication.getInstance().addActivity(this);

3、退出菜单调用exit()方法