Android中安全退出程序的六种方法

1. Dalvik VM的本地方法

//杀死进程
android.os.Process.killProcess(android.os.Process.myPid())
//抛异常强制退出
System.exit(0);

2.任务管理器方法

//通过activity管理器重启
ActivityManager activitymanager= (ActivityManager)getSystemService (Context.ACTIVITY_SERVICE);
activitymanager.restartPackage(getPackageName());

注意：需要注册的权限<uses-permission android:name=\"android.permission.RESTART_PACKAGES\"></uses-permission>

3.通过封装到栈里一一结束

//封装界面的容器
List<Activity> activitylist=new LinkedList<Activity>();
//定义我的应用
public static MyApplication instance;
    /*实例化我的应用的方法
    * 如果我的应用为空的话
    * 实例化我的应用
    */
public MyApplication getInstance(){
   if(null==instance){
    
   instance=new MyApplication();
     }
  return instance;
}
/*添加界面的方法
  * 直接调用界面添加
  */
public  void addActivity(Activity activity){
  activitylist.add(activity);
}
/*完全退出我的应用
  * 结束每一个界面
  * 抛异常强制退出
  */
public void exit(){
for(Activity activity :activitylist){
   activity.finish();
      }
     System.exit(0);
}

4. 根据Activity的声明周期
我们知道Android的窗口类提供了历史栈，我们可以通过stack的原理来巧妙的实现，这里我们在A窗口打开B 窗口时在Intent中直接加入标志 Intent.FLAG_ACTIVITY_CLEAR_TOP，这样开启B时将会清除该进程空间的所有Activity。
在A窗口中使用下面的代码调用B窗口

Intent intent = new Intent();
intent.setClass(MainActivity.this, SecondActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);  //注意本行的FLAG设置
startActivity(intent); 

5.自定义一个Actiivty 栈
通过利用一个单例模式的Activity栈来管理所有Activity。并提供退出所有Activity的方法。代码如下：

public class ScreenManager {
private static Stack<Activity> activityStack;
private static ScreenManager instance;
private  ScreenManager(){
}
public static ScreenManager getScreenManager(){
  if(instance==null){
   instance=new ScreenManager();
  }
  return instance;
}
//退出栈顶Activity
public void popActivity(Activity activity){
  if(activity!=null){
   activity.finish();
   activityStack.remove(activity);
   activity=null;
  }
}

//获得当前栈顶Activity
public Activity currentActivity(){
  Activity activity=activityStack.lastElement();
  return activity;
}

//将当前Activity推入栈中
public void pushActivity(Activity activity){
  if(activityStack==null){
   activityStack=new Stack<Activity>();
  }
  activityStack.add(activity);
}
//退出栈中所有Activity
public void popAllActivityExceptOne(Class cls){
  while(true){
   Activity activity=currentActivity();
   if(activity==null){
    break;
   }
   if(activity.getClass().equals(cls) ){
    break;
   }
   popActivity(activity);
  }
}
} 

6.通过封装超类管里栈继承实现
1.

public class ActivityManager {                  
private Context context;                  
private static ActivityManager activityManager;                  
public static ActivityManager getActivityManager(Context context){                

if(activityManager == null){                         
   activityManager = new ActivityManager(context);                

}                
return activityManager;     

}                  

private ActivityManager(Context context){               
  this.context = context;         
}                 

 /** * task map，用于记录activity栈，方便退出程序（这里为了不影响系统回收activity，所以用软引用）*/       

private final HashMap<String, SoftReference<Activity>> taskMap = new HashMap<String, SoftReference<Activity>>();                  

/*** 往应用task map加入activity*/       

public final void putActivity(Activity atv) {                

taskMap.put(atv.toString(), new SoftReference<Activity>(atv));        

}                  

/*** 往应用task map加入activity*/       

public final void removeActivity(Activity atv)

{                

taskMap.remove(atv.toString());        

}                  

/*** 清除应用的task栈，如果程序正常运行这会导致应用退回到桌面 */       

public final void exit() {                 

for (Iterator<Entry<String, SoftReference<Activity>>> iterator = taskMap.entrySet().iterator(); iterator.hasNext();)

{                       

 SoftReference<Activity> activityReference =  iterator.next().getValue();                        

Activity activity = activityReference.get();                        
if (activity != null) {                                

activity.finish();                        

}               
}

taskMap.clear();       

}  

} 

2、创建自己的根activity，重写onCreate与onDestory

public class BaseActivity extends Activity {                  

private ActivityManager manager = ActivityManager.getActivityManager(this);                  

@Override       

protected void onCreate(Bundle savedInstanceState) {                

super.onCreate(savedInstanceState);                

manager.putActivity(this);        

}          

@Override       

protected void onDestroy() {                

super.onDestroy();                

manager.removeActivity(this);        

}                  

public void exit(){               

 manager.exit();        

}          

} 

3、以后创建的activity都继承这个根activity就可以了，如下：

public class ExitActivity extends BaseActivity implements OnClickListener{                  

private Button start;                  

private Button exit;                  

private TextView tipTV;                        

@Override   

public void onCreate(Bundle savedInstanceState) {        

super.onCreate(savedInstanceState);        

setContentView(R.layout.main);        

start = (Button)findViewById(R.id.start_new_activity);        

exit = (Button)findViewById(R.id.exit_all_activity);        

tipTV = (TextView)findViewById(R.id.tip_tv);        

tipTV.setText("activity:"+this.toString());                  

start.setOnClickListener(this);        

exit.setOnClickListener(this);    

}            

@Override       

public void onClick(View v) {                

if(v == start){                        

Intent intent = new Intent(this , ExitActivity.class);                        

startActivity(intent);                

}else if(v == exit){                        

exit();                

}        

}

}