android---多Activity一次性退出

因为android的API中没有提供一次性退出的接口所以想要在多activity的程序里面一次性退出的话就要费点功夫了。我是在一个单例对象里面记录activity栈中activity的引用然后在需要退出时遍历一遍finish()掉就可以了。实现步骤如下：
1、创建一个单例对象

package com.exit;

import java.lang.ref.SoftReference;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;

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


package com.exit;

import android.app.Activity;
import android.os.Bundle;

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

package com.exit.activitys;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

import com.exit.BaseActivity;
import com.exit.R;

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();
               }
        }
}