域服务 - 服务器侧更新

Question

我有一个Silverlight 4 RIA域服务。在一个特定的方法中，我需要在数据库中更改一个值（当然是其他事情）。要执行此操作，我得到实体，更改一个值，然后我需要将其保存回DB。

我已经尝试呼叫实体的生成更新函数，只需调用它.ObjectContext.myentity.attachasmodifed（无神透）;但更改永远不会回到数据库。

如何将值从服务器端保存（即，客户端从未有此数据）？

Answer 1

Turns out, attaching the object before or after the change makes no difference. The missing peice was :

this.ObjectContext.SaveChanges();

Answer 2

You should know that the UpdateXXX method doesn't actually submit the changes to the database - that only happens a bit later. knowing this, we can change the default implementation of the UpdateXXX method: (I'm assuming XXX == Product here)

    public void UpdateProduct(Product currentProduct)
    {
        this.ObjectContext.Products.AttachAsModified(currentProduct, this.ChangeSet.GetOriginal(currentProduct));
    }

to

    public void UpdateProduct(Product currentProduct)
    {
        // This line only reattach the entity back to EF context, it doesn't submit changes yet
        this.ObjectContext.Products.AttachAsModified(currentProduct, this.ChangeSet.GetOriginal(currentProduct));

        currentProduct.SomeProperty = "SomeChange"; // This change is going to be submitted later
    }