在APP开发中，很多情况下，我们需要统一管理所有Activity。因为 不仅能实现在应用退出时关闭所有activity,还能实现获取当前Activity上一个Activity、寻找某个类型的Activity、结束某个Activity，以及Activity之间的跳转等操作。

以往的实现方式也很多，都比较麻烦，但是幸运的是API 14之后，在Application类中，提供了一个应用生命周期回调的注册方法，用来对应用的生命周期进行集中管理，这个接口叫registerActivityLifecycleCallbacks，可以通过它注册自己的ActivityLifeCycleCallback，每一个Activity的生命周期都会回调到这里的对应方法。

Activity生命周期图：

Activity生命周期.png

ActivityLifecycleCallbacks接口代码：

回调方法.png

这种方式实现起来非常简洁，通俗易懂，下面贴出我的实现

AppManageHelper

/**
 * Activity统一管理的辅助类
 * <p>
 * 作者： 周旭 on 2017年9月15日 0015.
 * 邮箱：374952705@qq.com
 * 博客：http://www.jianshu.com/u/56db5d78044d
 */

public class AppManageHelper {

    private static final String TAG = "AppManageHelper";

    /**
     * 维护Activity 的list
     */
    public static List<Activity> mActivityList = Collections
            .synchronizedList(new LinkedList<Activity>());

    /**
     * @param activity 作用说明 ：添加一个activity到管理里
     */
    public static void pushActivity(Activity activity) {
        mActivityList.add(activity);
        Log.i(TAG, "activityList:size:" + mActivityList.size());
    }

    /**
     * @param activity 作用说明 ：删除一个activity在管理里
     */
    public static void popActivity(Activity activity) {
        mActivityList.remove(activity);
        Log.i(TAG, "activityList:size:" + mActivityList.size());
    }

    /**
     * get current Activity 获取当前Activity（栈中最后一个压入的）
     */
    public static Activity currentActivity() {
        if (mActivityList == null || mActivityList.isEmpty()) {
            return null;
        }
        Activity activity = mActivityList.get(mActivityList.size() - 1);
        return activity;
    }

    /**
     * 结束当前Activity（栈中最后一个压入的）
     */
    public static void finishCurrentActivity() {
        if (mActivityList == null || mActivityList.isEmpty()) {
            return;
        }
        Activity activity = mActivityList.get(mActivityList.size() - 1);
        finishActivity(activity);
    }

    /**
     * 结束指定的Activity
     */
    public static void finishActivity(Activity activity) {
        if (mActivityList == null || mActivityList.isEmpty()) {
            return;
        }
        if (activity != null) {
            mActivityList.remove(activity);
            activity.finish();
            activity = null;
        }
    }

    /**
     * 结束指定类名的Activity
     */
    public static void finishActivity(Class<?> cls) {
        if (mActivityList == null || mActivityList.isEmpty()) {
            return;
        }
        for (Activity activity : mActivityList) {
            if (activity.getClass().equals(cls)) {
                finishActivity(activity);
            }
        }
    }

    /**
     * 按照指定类名找到activity
     *
     * @param cls
     * @return
     */
    public static Activity findActivity(Class<?> cls) {
        Activity targetActivity = null;
        if (mActivityList != null) {
            for (Activity activity : mActivityList) {
                if (activity.getClass().equals(cls)) {
                    targetActivity = activity;
                    break;
                }
            }
        }
        return targetActivity;
    }

    /**
     * @return 作用说明 ：获取当前最顶部activity的实例
     */
    public Activity getTopActivity() {
        Activity mBaseActivity = null;
        synchronized (mActivityList) {
            final int size = mActivityList.size() - 1;
            if (size < 0) {
                return null;
            }
            mBaseActivity = mActivityList.get(size);
        }
        return mBaseActivity;

    }

    /**
     * @return 作用说明 ：获取当前最顶部的acitivity 名字
     */
    public String getTopActivityName() {
        Activity mBaseActivity = null;
        synchronized (mActivityList) {
            final int size = mActivityList.size() - 1;
            if (size < 0) {
                return null;
            }
            mBaseActivity = mActivityList.get(size);
        }
        return mBaseActivity.getClass().getName();
    }

    /**
     * 结束所有Activity
     */
    public static void finishAllActivity() {
        if (mActivityList == null) {
            return;
        }
        for (Activity activity : mActivityList) {
            activity.finish();
        }
        mActivityList.clear();
    }

    /**
     * 退出应用程序
     */
    public static void exitApp() {
        try {
            Log.i(TAG, "app exit");
            finishAllActivity();
        } catch (Exception e) {
        }
    }
}

Application

public class MyApplication extends MultiDexApplication {

    public static Context mContext;
   
    @Override
    public void onCreate() {
        super.onCreate();
      
        //注册Activity生命周期回调的统一管理
        registerActivityLifecycleCallbacks(new SwitchBackgroundCallbacks());
    }



    //activity生命的回调
    private class SwitchBackgroundCallbacks implements ActivityLifecycleCallbacks {

        @Override
        public void onActivityCreated(Activity activity, Bundle bundle) {
            /**
             *  监听到 Activity创建事件 将该 Activity 加入list
             */
            AppManageHelper.pushActivity(activity);
        }

        @Override
        public void onActivityStarted(Activity activity) {

        }

        @Override
        public void onActivityResumed(Activity activity) {

        }

        @Override
        public void onActivityPaused(Activity activity) {

        }

        @Override
        public void onActivityStopped(Activity activity) {

        }

        @Override
        public void onActivitySaveInstanceState(Activity activity, Bundle bundle) {

        }

        @Override
        public void onActivityDestroyed(Activity activity) {
            if (null== AppManageHelper.mActivityList||AppManageHelper.mActivityList.isEmpty()){
                return;
            }
            if (AppManageHelper.mActivityList.contains(activity)){
                /**
                 *  监听到 Activity销毁事件 将该Activity 从list中移除
                 */
                AppManageHelper.popActivity(activity);
            }
        }
    }
}