项目开启的Activity越多，占的内存越多，我们是不是有时候想当我打开很多界面的时候，我们到底打开多少个Activity，OK现在你的难题解决了，只有把这个Activity管理类复制到你的项目当中，随时随地管理的你的Activity，让你成为内存的主导者！不要问我叫什么，请叫我雷锋！首先看看效果图：

代码献上：

/**
 * 2014-6-7 上午10:40:16
 */
package com.jiub.client.mobile.manager;

import java.util.Stack;

import android.app.Activity;

import com.jiub.client.mobile.utils.QLog;

/**
 * @author zqy
 *
 * 
 */
public class ScreenManager {
	
	private final static String TAG=ScreenManager.class.getSimpleName();
	
	
   private static Stack<Activity> activityStack;
   private static ScreenManager instance;
    
   public static ScreenManager getScreenManager(){
        if (instance == null) {
            instance = new ScreenManager();
        }
        QLog.i(TAG, "ScreenManager create");
        return instance;
        
    }
    
    /**
     * 从栈中移除最后一个元??
     */
    public void popActivity(){
        Activity activity = currentActivity();
        if (activity != null) {
            if (!activity.isFinishing()) {
                activity.finish();
            }
            activityStack.removeElement(activity);
            activity = null;
        }
        QLog.i(TAG, "ScreenManager popActivity ");
        
    }
    
    /**
     * 从栈中移除指定的元素
     * @param activity
     */
    public void popActivity(Activity activity){
        if (activity != null) {
        	QLog.i(TAG, "要删除"+activity.getClass().getSimpleName());
            if (!activity.isFinishing()) {
                activity.finish();
                QLog.i(TAG, activity.getClass().getSimpleName()+"正在关闭");
            }else{
            	QLog.i(TAG, activity.getClass().getSimpleName()+"已经关闭");
            }
            
            activityStack.removeElement(activity);
            QLog.i(TAG, activity.getClass().getSimpleName()+"从栈中移除");
            activity = null;
        }
        
        int size=activityStack.size();
        QLog.i(TAG, "删除后个数"+size);
    }

    /**
     * 将新元素添加到栈中
     * @param activity
     */
    public void pushActivity(Activity activity){
        if (activityStack == null) {
            activityStack = new Stack<Activity>();
        }
        activityStack.addElement(activity);
        
        QLog.i(TAG, "加入"+activity.getClass().getSimpleName());
        int size=activityStack.size();
        QLog.i(TAG, "添加后个数"+size);
    }
    
    /**
     * 获取栈顶元素
     * @return
     */
    public Activity currentActivity(){
        Activity activity = null;
        try {
            activity = activityStack.lastElement();
        } catch (Exception e) {
        }
        return activity;
    }
    
    /**
     * 移除全部元素，除了指定类型的以外
     * @param cls
     */
    public void popAllActivityExceptOne(Class<?> cls){
        int size = activityStack.size();
        for (int i = 0; i < size; i++) {
            Activity activity = activityStack.get(i);
            if (activity != null && activity.getClass().equals(cls)) {
            }else{
                popActivity(activity);
                size--;
                i--;
            }
        }
    }
    
    
    /**
     * 按照给定的Class，结束一个Activity
     * @param cls
     */
    public void finishActivityByClass(Class<?> cls){
        int size = activityStack.size();
        for (int i = 0; i < size; i++) {
            Activity activity = activityStack.get(i);
            if (activity != null && activity.getClass().equals(cls)) {
                popActivity(activity);
                size--;
                i--;
            }
        }
    }
    
}

protected ScreenManager mScreenManager;//初始化

mScreenManager = ScreenManager.getScreenManager();
		mScreenManager.pushActivity(this);

mScreenManager.popActivity(this);

Android Activity管理类优化内存利器非常方便