标题（30字内）：多亲AI助手深度解析：防沉迷+AI大模型原理与考点

// 传统方案：在应用入口简单判断时间
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        // 简单的时间判断
        int hour = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
        if (hour >= 22 || hour <= 6) {
            // 显示“禁止使用”提示
            Toast.makeText(this, "当前时段不可使用", Toast.LENGTH_SHORT).show();
            finish();
            return;
        }
        
        setContentView(R.layout.activity_main);
        // 正常加载应用...
    }
}

// 1. 在AndroidManifest.xml中申请必要权限
<uses-permission android:name="android.permission.GET_PACKAGE_SIZE" />
<uses-permission android:name="android.permission.PACKAGE_USAGE_STATS" />
<receiver android:name=".AdminReceiver" 
          android:permission="android.permission.BIND_DEVICE_ADMIN">
    <meta-data android:name="android.app.device_admin" 
               android:resource="@xml/device_admin_receiver" />
    <intent-filter>
        <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
    </intent-filter>
</receiver>

// 2. 防沉迷服务核心类 - 检测并强制关闭超时应用
public class AntiAddictionService extends Service {
    private UsageStatsManager usageStatsManager;
    private DevicePolicyManager devicePolicyManager;
    private Map<String, Long> appUsageTime = new HashMap<>();
    
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        startMonitoring();  // 启动监控线程
        return START_STICKY;
    }
    
    private void startMonitoring() {
        new Thread(() -> {
            while (isMonitoring) {
                // 获取当前前台应用包名
                String foregroundApp = getForegroundPackageName();
                if (foregroundApp != null && isRestrictedApp(foregroundApp)) {
                    // 累计使用时长
                    long usedTime = accumulateTime(foregroundApp);
                    long dailyLimit = getDailyLimit(foregroundApp);  // 从云端/本地配置读取
                    
                    if (usedTime >= dailyLimit) {
                        // 超限，强制关闭应用
                        devicePolicyManager = (DevicePolicyManager) 
                            getSystemService(Context.DEVICE_POLICY_SERVICE);
                        ComponentName adminReceiver = new ComponentName(this, AdminReceiver.class);
                        if (devicePolicyManager.isAdminActive(adminReceiver)) {
                            devicePolicyManager.setApplicationHidden(adminReceiver, 
                                foregroundApp, true);  // 隐藏应用
                            killAppProcess(foregroundApp);  // 强杀进程
                            
                            // 通知家长端
                            notifyParent(foregroundApp, usedTime);
                        }
                    }
                }
                Thread.sleep(1000);  // 每秒检测一次
            }
        }).start();
    }
    
    private String getForegroundPackageName() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            UsageStatsManager usageStatsManager = (UsageStatsManager) 
                getSystemService(Context.USAGE_STATS_SERVICE);
            long currentTime = System.currentTimeMillis();
            List<UsageStats> stats = usageStatsManager.queryUsageStats(
                UsageStatsManager.INTERVAL_DAILY, currentTime - 1000  60, currentTime);
            if (stats != null && !stats.isEmpty()) {
                // 按最后使用时间排序，取最近使用的应用
                stats.sort((s1, s2) -> 
                    Long.compare(s2.getLastTimeUsed(), s1.getLastTimeUsed()));
                return stats.get(0).getPackageName();
            }
        }
        return null;
    }
}