entity-framework - 自加载实体以来，实体可能已被修改或删除

Question

我在它们自己的上下文中执行代码，但这导致数据在主线程上下文中不同步。所以我需要在其他上下文完成工作后刷新实体，然后才能更新它。

不幸的是，我收到了 OptimisticConcurrencyException 并且无法弄清楚是哪个实体是问题并且需要刷新？有没有办法找出导致 OptimisticConcurrencyException 的实体？此消息根本没有帮助...

System.Data.Entity.Infrastructure.DbUpdateConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries. ---> System.Data.OptimisticConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.

Answer 1

也许最好的解决方案是创建一个新的 context在其他线程完成后在主线程上下文中。

否则，如果您需要重用 context ，这是刷新上下文对象的便捷方法。

    public void RefreshAll()
    {
        // Get all objects in state manager with entityKey
        // (context.Refresh will throw an exception otherwise)
        var refreshableObjects = (from entry in
                ObjectContext.ObjectStateManager.GetObjectStateEntries(
                                                    EntityState.Deleted
                                                  | EntityState.Modified
                                                  | EntityState.Unchanged)
                                  where entry.EntityKey != null
                                  select entry.Entity);

        ObjectContext.Refresh(RefreshMode.StoreWins, refreshableObjects);
    }