c# - 在 SaveChanges() 中返回字典

Question

我正在覆盖 SaveChanges()方法，以便我可以使用 ChangeTracker获取实体的修改属性。我需要返回 Dictionary<string, string>修改后的属性，以便在我的 Controller 中我可以调用 Audit Service .到目前为止，我的 SaveChanges() 方法如下所示:

public override int SaveChanges()
{
    var changeInfo = ChangeTracker.Entries()
        .Where(t => t.State == EntityState.Modified)
        .Select(t => new {
            Original = t.OriginalValues.PropertyNames.ToDictionary(pn => pn, pn => t.OriginalValues[pn]),
            Current = t.CurrentValues.PropertyNames.ToDictionary(pn => pn, pn => t.CurrentValues[pn])
        });

    Dictionary<string, string> modifiedProperties = new Dictionary<string, string>();
    foreach (var item in changeInfo)
    {
        foreach (var origValue in item.Original)
        {
            var currValue = item.Current[origValue.Key];
            if ((origValue.Value != null && currValue != null) && !origValue.Value.Equals(currValue))
            {
                modifiedProperties.Add(origValue.Key, string.Format("Old Value: {0}, New Value: {1}", origValue.Value, currValue));
            }
        }
    }
    return base.SaveChanges();
}

有没有办法访问modifiedProperties我的 Controller 中的字典，以便我可以将其传递给我的服务？

Controller :

if (validator.IsValid())
{
    _workRequestRepo.Save(workRequest);
    _auditService.Log(UserId, modelId, "Work Order", "Edit", modifiedProperties);
}

Answer 1

您不必返回修改后的属性，您可以在 SaveChanges 方法中处理您的审计过程。这是一个例子:

    public MyContainer(IUserProvider userProvider) {
        _userProvider = userProvider;
    }

    public override int SaveChanges() {
        var entities = ChangeTracker.Entries().Where(x => x.Entity is BaseEntity && (x.State == EntityState.Added || x.State == EntityState.Modified));
        if (entities.Any()) {
            User currentUser = _userProvider.GetCurrent();
            if (currentUser == null)
                throw new Exception("Current user is undefined.");
            DateTime time = DateTime.Now;
            foreach (var entity in entities) {
                BaseEntity baseEntity = (BaseEntity)entity.Entity;
                if (entity.State == EntityState.Added) {
                    baseEntity.Created = time;
                    baseEntity.CreatedBy = currentUser;
                }
                baseEntity.Modified = time;
                baseEntity.ModifiedBy = currentUser;

                // get and store the changed properties of the entity here
                // ....
                var changeInfo = entities.Select(t => new { Original = t.OriginalValues.PropertyNames.ToDictionary(pn => pn, pn => originalValues[pn]), Current = t.CurrentValues.PropertyNames.ToDictionary(pn => pn, pn => t.CurrentValues[pn]);

            }
        }

        return base.SaveChanges();
    }