11

我知道那里有几个类似的帖子，但我找不到任何解决此问题的方法。

我想在 Entity Framework 6 中添加、更改或删除实体（软删除）时添加（某种）AudioLog。我已经覆盖了 SaveChanges，因为我只想为添加、修改或删除的 EntityStates 添加日志条目，我在第一次调用 SaveChanges 之前获取了列表。问题是，因为我需要记录已执行的操作，所以我需要检查实体的 EntityState。但是在调用 SaveChanges 之后，所有条目的 EntityState 都未更改。

public override int SaveChanges()
{
    using (var scope = new TransactionScope())
    {
        var modifiedEntries = ChangeTracker.Entries()
            .Where(e => e.State == EntityState.Added || e.State == EntityState.Deleted || e.State == EntityState.Modified)
            .ToList();

        int changes = base.SaveChanges();
        foreach (var entry in modifiedEntries)
        {
            ApplyAuditLog(entry);
        }

        base.SaveChanges();
        scope.Complete();
        return changes;
    }
}

private void ApplyAuditLog(DbEntityEntry entry)
{
    ILog entity = entry.Entity as ILog;

    if (entity != null)
    {
        LogOperation operation;
        switch (entry.State)
        {
            case EntityState.Added:
                operation = LogOperation.CreateEntity;
                break;
            case EntityState.Deleted:
                operation = LogOperation.DeleteEntity;
                break;
            case EntityState.Modified:
                operation = LogOperation.UpdateEntity;
                break;
            default:
                throw new ArgumentOutOfRangeException();
        }

        AuditLog log = new AuditLog
        {
            Created = DateTime.Now,
            Entity = entry.Entity.GetType().Name,
            EntityId = entity.Id,
            Operation = operation,
        };

        AuditLog.Add(log);
    }
}
4

2 回答 2

17

啊……当然了！！对于新添加的实体，id 只会是一个“问题”，因此通过将列表分成两个（一个用于修改/删除，一个用于添加），我分两个阶段创建 AuditLog。

对于其他想要应用这种 AuditLog 的人，这是我的工作代码：

public override int SaveChanges()
{
    using (var scope = new TransactionScope())
    {
        var addedEntries = ChangeTracker.Entries().Where(e => e.State == EntityState.Added).ToList();
        var modifiedEntries = ChangeTracker.Entries().Where(e => e.State == EntityState.Deleted || e.State == EntityState.Modified).ToList();

        foreach (var entry in modifiedEntries)
        {
            ApplyAuditLog(entry);
        }

        int changes = base.SaveChanges();
        foreach (var entry in addedEntries)
        {
            ApplyAuditLog(entry, LogOperation.CreateEntity);
        }

        base.SaveChanges();
        scope.Complete();
        return changes;
    }
}

private void ApplyAuditLog(DbEntityEntry entry)
{
    LogOperation operation;
    switch (entry.State)
    {
        case EntityState.Added:
            operation = LogOperation.CreateEntity;
            break;
        case EntityState.Deleted:
            operation = LogOperation.DeleteEntity;
            break;
        case EntityState.Modified:
            operation = LogOperation.UpdateEntity;
            break;
        default:
            throw new ArgumentOutOfRangeException();
    }

    ApplyAuditLog(entry, operation);
}

private void ApplyAuditLog(DbEntityEntry entry, LogOperation logOperation)
{
    ILog entity = entry.Entity as ILog;

    if (entity != null)
    {
        AuditLog log = new AuditLog
        {
            Created = DateTime.Now,
            Entity = entry.Entity.GetType().Name,
            EntityId = entity.Id,
            Operation = logOperation,
        };
        AuditLog.Add(log);
    }
}
于 2013-11-06T11:59:47.393 回答
0

您可以将 EntityState 保存到 Entity 键值对并在第一次更改后使用它。

var entries = this.ChangeTracker.Entries() .Where(e => e.State == EntityState.Added || e.State == EntityState.Modified || e.State == EntityState.Deleted) .Select(e = > 新 { e.State, e }).ToList();

于 2021-04-17T12:24:05.013 回答