重寫信眾編號程式

web/App_Code/Model/Partial/follower.cs

@@ -190,20 +190,86 @@ namespace Model
         public static string generate_f_number(string sex = "男眾")
         {
             string selectedSex = sex;
-            string f_number = selectedSex == "男眾" ? "M" : "F";
             var datePart = DateTime.Now.ToString("yyyyMMdd");
-            f_number += datePart;
-
-
-            int nextSerial = 1;
             
-            lock (GlobalVariables.FNumberLock)
+            // 使用重試機制確保不重號
+            int maxRetries = 5;
+            for (int retry = 0; retry < maxRetries; retry++)
             {
-                nextSerial = (int)HttpContext.Current.Application["FNumberSerial"] + 1;
-                HttpContext.Current.Application["FNumberSerial"] = nextSerial;
+                try
+                {
+                    using (var _db = new Model.ezEntities())
+                    using (var transaction = _db.Database.BeginTransaction())
+                    {
+                        // 在交易中查詢最大序號
+                        int nextSerial = GetNextSerialFromDatabase(_db, datePart, selectedSex);
+                        string f_number = GenerateFNumber(selectedSex, datePart, nextSerial);
+                        
+                        // 立即檢查是否重複（在交易中）
+                        if (!_db.followers.Any(f => f.f_number == f_number))
+                        {
+                            transaction.Commit();
+                            return f_number;
+                        }
+                        
+                        // 如果重複，回滾交易並重試
+                        transaction.Rollback();
+                        
+                        // 短暫延遲後重試
+                        if (retry < maxRetries - 1)
+                        {
+                            System.Threading.Thread.Sleep(10 + retry * 5); // 10ms, 15ms, 20ms, 25ms
+                        }
+                    }
+                }
+                catch (Exception ex)
+                {
+                    System.Diagnostics.Debug.WriteLine($"生成編號失敗 (重試 {retry + 1}): {ex.Message}");
+                    if (retry == maxRetries - 1)
+                    {
+                        // 最後一次重試失敗，使用時間戳記確保唯一性
+                        return GenerateFNumberWithTimestamp(selectedSex, datePart);
+                    }
+                }
             }
-            f_number += nextSerial.ToString("D5");
-            return f_number;
+            
+            // 如果所有重試都失敗，使用時間戳記
+            return GenerateFNumberWithTimestamp(selectedSex, datePart);
+        }
+
+        private static int GetNextSerialFromDatabase(Model.ezEntities _db, string datePart, string sex)
+        {
+            var prefix = sex == "男眾" ? "M" : "F";
+            var searchPattern = prefix + datePart;
+            
+            var maxFNumber = _db.followers
+                .Where(m => 
+                    m.f_number.Length == 14 &&
+                    m.f_number.StartsWith(searchPattern))
+                .OrderByDescending(m => m.f_number)
+                .Select(m => m.f_number)
+                .FirstOrDefault();
+
+            if (!string.IsNullOrEmpty(maxFNumber))
+            {
+                var serialPart = maxFNumber.Substring(9, 5);
+                return int.Parse(serialPart) + 1;
+            }
+            return 1;
+        }
+
+        private static string GenerateFNumber(string sex, string datePart, int serial)
+        {
+            string prefix = sex == "男眾" ? "M" : "F";
+            return prefix + datePart + serial.ToString("D5");
+        }
+
+        private static string GenerateFNumberWithTimestamp(string sex, string datePart)
+        {
+            // 使用時間戳記確保唯一性（最後手段）
+            string prefix = sex == "男眾" ? "M" : "F";
+            var timestamp = DateTime.Now.ToString("HHmmss");
+            return prefix + datePart + timestamp;
         }
     }