如何刷新DbContext [英] How to Refresh DbContext

问题描述

我想刷新我的 DbContext 的所有实体，而无需重新创建它，我尝试了以下操作，但没有一个有意义：

I want to refresh all entities of my DbContext without recreating it, I tried the following and none of them make sense:

var context = ((IObjectContextAdapter)myDbContext).ObjectContext;

var refreshableObjects = (from entry in context.ObjectStateManager.GetObjectStateEntries(
                                   EntityState.Added
                                   | EntityState.Deleted
                                   | EntityState.Modified
                                   | EntityState.Unchanged)
                          where entry.EntityKey != null
                          select entry.Entity);

context.Refresh(RefreshMode.StoreWins, refreshableObjects);
//.......................................................................
foreach (var entry in this.Orm.ChangeTracker.Entries())
{
    entry.State = EntityState.Unchanged;
}
this.Orm.ChangeTracker.DetectChanges();

也是唯一刷新我的 DbContext 的对象：

And the only one which refreshes my DbContext:

foreach (var i in this.Orm.ChangeTracker.Entries())
    i.Reload();

但这太慢了。您能帮我选择正确的方法吗？

But it's too slow. Can you help me choosing the right way?

推荐答案

我刚刚发现 Enumerable 结果应该被评估，因为 Refresh 方法将其作为对象而不对其进行评估。

I just found that the Enumerable result should be evaluated because the Refresh method gets it as object and doesn't evaluate it.

var context = ((IObjectContextAdapter)myDbContext).ObjectContext;
var refreshableObjects = (from entry in context.ObjectStateManager.GetObjectStateEntries(
                                           EntityState.Added
                                           | EntityState.Deleted
                                           | EntityState.Modified
                                           | EntityState.Unchanged)
                          where entry.EntityKey != null
                          select entry.Entity).ToList();

context.Refresh(RefreshMode.StoreWins, refreshableObjects);

我更喜欢以下内容：

var refreshableObjects = myDbContext.ChangeTracker.Entries().Select(c=>c.Entity).ToList();
context.Refresh(RefreshMode.StoreWins, refreshableObjects);

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