具有 MVVM 和 WCF Ria 服务的 Silverlights Dataform
晚上好，
我正在寻找有人帮助我了解如何使用 WCF Ria 服务将 Silverlight DataForm 与我的 ViewModel 结合起来。我想要完成的是使用 DataForm 管理我的实体集合并利用其内置的导航、添加、编辑和删除功能。然而，我在将它们与我的 ViewModel 和 Ria 服务结合在一起时遇到了麻烦。
根据我的理解，DataForm 需要绑定到 ObservableCollection
_context.Load(_context.GetAllCustomersQuery(), loadCustomersQueryCallback, true);
我将在回调方法中收到一个 IQueryable，我必须像这样将其转换为 ObservableCollection 吗？
Customers = new ObservableCollection
Customers 是我的 ViewModel 中的一个属性，如下所示...
public ObservableCollection<Customer> Customers
{
get { return _customers; }
set
{
if (_customers != value)
{
_customers = value;
OnPropertyChanged("Customers");
}
}
}
DataForm 绑定到 ViewModel 的 Customers 属性，我能够看到数据源中的数据，我可以在实体之间导航，我可以编辑现有实体并将更改保留回数据库，但是我无法添加或删除实体。
我对客户财产所做的事情正确吗？我是否通过转换为新的 ObservableCollection 来“断开”与上下文的连接，因此实际上并未从上下文中添加或删除实体？
非常感谢任何帮助。
问候，
Good evening,
I am looking for someone to help me with my understanding of how to incorporate the Silverlight DataForm with my ViewModel that using WCF Ria Services. What I am trying to accomplish is using the DataForm manage my collection of entity and utilize its built in navigation, Add, Edit and Delete functionality. Howerver, I am having trouble tying it all together with my ViewModel and Ria Services.
From my understanding, the DataForm needs to be bound to an ObservableCollection<T>. However when I query from the WCF Ria Service context. ie.
_context.Load(_context.GetAllCustomersQuery(), loadCustomersQueryCallback, true);
I will receive back an IQueryable in the callback method, which i would have to cast as an ObservableCollection<T> like so?
Customers = new ObservableCollection<Customer>(_context.Customers);
Customers is a property in my ViewModel like so...
public ObservableCollection<Customer> Customers
{
get { return _customers; }
set
{
if (_customers != value)
{
_customers = value;
OnPropertyChanged("Customers");
}
}
}
The DataForm is bound to the Customers Property of the ViewModel and I am able to see the data from my datasource, I can navigate between entities, I can edit an existing entity and persist the changes back to the database however I cannot add or delete entites.
Is what I'm doing with the Customers property correct? have I "disconnected" from the context by casting into a new ObservableCollection and therefore have not actually added or removed the entities from the context?
Any help is greatly appreciated.
Regards,
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你可以使用：
You could use :
我认为你在最后一个问题中谈到了这个问题。当您创建新的 ObservableCollection 时，您已与集合更改跟踪（添加和删除）断开连接。除了使用 OC，还有许多其他选项值得考虑。在您的情况下，看起来 EntitySet 或 EntityList 可能是最好的选择。有关这些类型的完整概述，请查看我在 RIA 服务 SP1 中的集合绑定。
I think you hit on the issue in your last question. When you create a new ObservableCollection, you've disconnected from collection change tracking (adds and deletes). Instead of using OC, there are a number of other options worth considering. In your case, it looks like EntitySet or EntityList may be the best options. For a full rundown of these types, take a look at my post on collection binding in RIA Services SP1.