获取app中所有activity集合

package cn.com.dhcc.di.ducha.utils;

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

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * Created by fhk on 2017/11/6.
 */

public class ActivityListUtil {

    public static List getActivitiesByApplication(Application application) {
        List list = new ArrayList<>();
        try {
            Class applicationClass = Application.class;
            Field mLoadedApkField = applicationClass.getDeclaredField("mLoadedApk");
            mLoadedApkField.setAccessible(true);
            Object mLoadedApk = mLoadedApkField.get(application);
            Class mLoadedApkClass = mLoadedApk.getClass();
            Field mActivityThreadField = mLoadedApkClass.getDeclaredField("mActivityThread");
            mActivityThreadField.setAccessible(true);
            Object mActivityThread = mActivityThreadField.get(mLoadedApk);
            Class mActivityThreadClass = mActivityThread.getClass();
            Field mActivitiesField = mActivityThreadClass.getDeclaredField("mActivities");
            mActivitiesField.setAccessible(true);
            Object mActivities = mActivitiesField.get(mActivityThread);
            // 注意这里一定写成Map，低版本这里用的是HashMap，高版本用的是ArrayMap
            if (mActivities instanceof Map) {
                @SuppressWarnings("unchecked")
                Map, Object> arrayMap = (Map, Object>) mActivities;
                for (Map.Entry, Object> entry : arrayMap.entrySet()) {
                    Object value = entry.getValue();
                    Class activityClientRecordClass = value.getClass();
                    Field activityField = activityClientRecordClass.getDeclaredField("activity");
                    activityField.setAccessible(true);
                    Object o = activityField.get(value);
                    list.add((Activity) o);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            list = null;
        }
        return list;
    }
}