清空所有Activity

- 日理万妓 2022-12-03 09:13 174阅读 0赞

退出APP是需要清空所有Activity， 清空的前提是 需要记录已开启的所有 Activity。  
在Application.ActivityLifecycleCallbacks的生命周期中调用add和remove操作。

public class ActivityStackHelper { 
        private static LinkedHashMap<Class<?>, Activity> activities = new LinkedHashMap<>();
    
        /** * 保存activity到集合中 * * @param activity */
        public static void add(Activity activity) { 
            if (activity == null) { 
                return;
            }
            activities.put(activity.getClass(), activity);
        }
    
        /** * 判断指定的activity在map中是否存在 * * @param clazz 指定的activity */
        public static boolean isActivityExist(Class clazz) { 
            return clazz != null && get(clazz) != null;
        }
    
        /** * 获取指定clazz的activity * * @param clazz * @param <T> * @return */
        public static <T extends Activity> T get(Class<T> clazz) { 
            return (T) activities.get(clazz);
        }
    
        /** * 获取当前集合中的activity * * @return */
        public static int getSize() { 
            return activities.size();
        }
    
        /** * 指定activity是否是activity栈中最底层的activity * * @param activity * @return true，是；false，否 */
        public static boolean isLastActivity(Activity activity) { 
            if (activity == null) { 
                return false;
            }
            if (activities == null || activities.size() == 0) { 
                return false;
            }
    
            ListIterator<Map.Entry<Class<?>, Activity>> iterator =
                    new ArrayList<>(activities.entrySet()).listIterator(activities.size());
    
            while (iterator.hasPrevious()) { 
                Map.Entry<Class<?>, Activity> next = iterator.previous();
                if (next.getKey() == activity.getClass()) { 
                    return !iterator.hasPrevious();
                }
            }
    
            return false;
        }
    
        /** * 移除集合中的activity * * @param activity */
        public static void remove(Activity activity) { 
            if (activity == null) { 
                return;
            }
            activities.remove(activity.getClass());
        }
    
        /** * 清空并finish所有activity */
        public static void clearAndFinishActivity() { 
            Set<Map.Entry<Class<?>, Activity>> entries = activities.entrySet();
            for (Map.Entry<Class<?>, Activity> entry : entries) { 
                Activity activity = entry.getValue();
                if (!activity.isFinishing()) { 
                    activity.finish();
                }
            }
            activities.clear();
        }
    
        /** * 清空并finish所有activity(除指定activity之外) * * @param clazzs */
        public static void clearAndFinishOtherActivity(Class... clazzs) { 
    
            List<Class> cls = clazzs != null ? Arrays.asList(clazzs) : null;
            Iterator<Map.Entry<Class<?>, Activity>> iterator = activities.entrySet().iterator();
            while (iterator.hasNext()) { 
                Map.Entry<Class<?>, Activity> next = iterator.next();
                Class<?> key = next.getKey();
                if (cls != null && cls.contains(key)) { 
                    continue;
                }
                Activity value = next.getValue();
                if (!value.isFinishing()) { 
                    value.finish();
                }
                iterator.remove();
            }
        }
    
        /** * 指定activity是否在运行 * * @param clazz * @param <T> * @return */
        public static <T extends Activity> boolean isActivityRunning(Class<T> clazz) { 
            T activity = get(clazz);
            if (activity == null || activity.isFinishing() || (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1 && activity.isDestroyed())) { 
                return false;
            } else { 
                return true;
            }
        }
    
        /** * 获取当前栈顶activity * * @return */
        public static Activity getTopActivity() { 
            if (activities == null || activities.size() == 0) { 
                return null;
            }
            Iterator<Map.Entry<Class<?>, Activity>> iterator = activities.entrySet().iterator();
            Map.Entry<Class<?>, Activity> next = null;
            while (iterator.hasNext()) { 
                next = iterator.next();
            }
            return next != null ? next.getValue() : null;
        }
    
    
        /** * 获取次栈顶activity * * @return */
        public static Activity getTopSecondActivity() { 
            if (activities == null || activities.size() == 0) { 
                return null;
            }
            int size = activities.size();
            if (size < 2){ 
                return null;
            }
            int index = 1;
            Iterator<Map.Entry<Class<?>, Activity>> iterator = activities.entrySet().iterator();
            Map.Entry<Class<?>, Activity> next = null;
            while (iterator.hasNext()) { 
                next = iterator.next();
                if (index == size - 1){ 
                    if (next != null){ 
                        LogUtils.i("ActivityStackHelper", "secondActivity" + next.getValue());
                        return next.getValue();
                    }
                }
                index++;
            }
            return null;
        }
    
        /** * 获取除了指定activity之外的栈顶activity * * @param clazz * @return */
        public static Activity getTopActivityExclude(Class clazz) { 
            if (activities == null || activities.size() == 0) { 
                return null;
            }
            Iterator<Map.Entry<Class<?>, Activity>> iterator = activities.entrySet().iterator();
            Map.Entry<Class<?>, Activity> resule = null;
            while (iterator.hasNext()) { 
                Map.Entry<Class<?>, Activity> next = iterator.next();
                if (next.getKey() != clazz) { 
                    resule = next;
                }
            }
            return resule != null ? resule.getValue() : null;
        }
    
    }

调用使用方法

public class AppActivityLifecycleCallbacks implements Application.ActivityLifecycleCallbacks { 
        @Override
        public void onActivityCreated(Activity activity, Bundle savedInstanceState) { 
            ActivityStackHelper.add(activity);
        }
        @Override
        public void onActivityDestroyed(Activity activity) { 
            ActivityStackHelper.remove(activity);
        }
      }

上述工具类用到了LinkedHashMap 是为了保证顺序，其特性详见 https://blog.csdn.net/iblade/article/details/108369770