添加项目文件。

鞋子止滑性能测试仪/PasswordExpirationService.cs

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+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace 鞋子止滑性能测试仪
+{
+    internal class PasswordExpirationService
+    {
+        private readonly TimeSpan _maxExpirationPeriod;
+        private readonly TimeSpan _reminderPeriod;
+
+        public PasswordExpirationService()
+        {
+            // 读取配置文件中的密码时效策略
+            var config = ConfigurationManager.AppSettings;
+            _maxExpirationPeriod = TimeSpan.FromDays(int.Parse(config["MaxExpirationPeriodInDays"]));
+            _reminderPeriod = TimeSpan.FromDays(int.Parse(config["ReminderPeriodInDays"]));
+        }
+
+        public bool IsPasswordExpired(DateTime passwordLastModified)
+        {
+            // 计算密码当前的有效期
+            TimeSpan passwordExpirationPeriod = passwordLastModified + _maxExpirationPeriod - DateTime.Now;
+            return passwordExpirationPeriod < TimeSpan.Zero;
+        }
+
+        public bool IsPasswordExpiringSoon(DateTime passwordLastModified)
+        {
+            // 判断密码是否接近过期提醒期
+            TimeSpan passwordExpirationPeriod = passwordLastModified + _maxExpirationPeriod - DateTime.Now;
+            return passwordExpirationPeriod < _reminderPeriod;
+        }
+    }
+}