fix .

Src/Dlhis.Canteen/Order/Request/OrderAddRequest.cs

@@ -44,7 +44,7 @@ public class OrderAddRequest : IValidatableObject
     /// </summary>
     public DateTime? CostDateTime { get; set; }
 
-    
+
     public bool IsUserId { get; set; }
 
 
@@ -58,9 +58,14 @@ public class OrderAddRequest : IValidatableObject
 
         CostDateTime ??= DateTime.Now;
 
+        if (!IsOffline)
+        {
+            (CostDateTime.Value.AddMinutes(5) < DateTime.Now).ThrowIfTrue("非法请求,时差超出允许范围");
+        }
+
         if (DeviceUniqueNo.IsEmpty())
         {
             yield return new ValidationResult("设备号不能为空", new[] { nameof(DeviceUniqueNo) });
         }
     }
-}
+}