MVVM-Light 工具包 V4 Beta 中的 IDataService

发布于 2024-12-09 08:57:03 字数 833 浏览 0 评论 0原文

我正在学习 Silverlight for WP7，并偶然发现了 MVVM Light 工具包。我认为学习最新的东西是个好主意，所以我安装了 V4 Beta。遗憾的是还没有任何文档（还？）。在模型文件夹中有 3 个文件，DataItem、DataService 和 IDataService。

public class DataItem
{
    public DataItem(string title)
    {
        Title = title;
    }

    public string Title { get; private set; }
}

public class DataService : IDataService
{
    public void GetData(Action<DataItem, Exception> callback)
    {
        // Use this to connect to the actual data service

        var item = new DataItem("Welcome to MVVM Light");
        callback(item, null);
    }
}

public interface IDataService
{
    void GetData(Action<DataItem, Exception> callback);
}

MainViewModel 使用这些类来获取属性的值。现在的问题是：这些是您应该使用的类（特别是 IDataService）吗？我似乎找不到有效使用它们的方法，因为 DataItem 仅包含一个字符串（或者它意味着用作基类？）。

原文

I'm learning Silverlight for WP7 and stumbled upon the MVVM Light toolkit. I thought it would be a good Idea to learn the newest thing so I installed the V4 Beta. Sadly there isn't any documentation to it (yet?).
In the Model-Folder there are 3 Files, DataItem, DataService and IDataService.

public class DataItem
{
    public DataItem(string title)
    {
        Title = title;
    }

    public string Title { get; private set; }
}

public class DataService : IDataService
{
    public void GetData(Action<DataItem, Exception> callback)
    {
        // Use this to connect to the actual data service

        var item = new DataItem("Welcome to MVVM Light");
        callback(item, null);
    }
}

public interface IDataService
{
    void GetData(Action<DataItem, Exception> callback);
}

These classes are used by the MainViewModel for getting the value of a property.
Now to the question: Are these the classes you should use (specifically IDataService)? I can't seem to find a way to use them effectively because the DataItem only contains a string (or is it meant to be used as a base class?).

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

浅唱ヾ落雨殇 2024-12-16 08:57:03

我已成功使用 IDataService 来提供测试和虚拟数据挂钩。您拥有的代码是您应该如何使用它的示例。 DataItem 是表示来自数据库或服务的数据的“实体”或“DTO（数据传输对象）”的示例。如果您使用 WCF，它将是您执行“添加服务引用”时生成的对象。 DataService 类是接口的表示。该 DataService 类将具有调用真实 Web 服务并执行 CRUD 操作的方法。您还可以拥有具有相同方法的 DesignTimeDataService: IDataService，但使用内存中的 foreach 创建数据。然后，您可以使用 IoC 或其他依赖注入在运行时注入实现。

在 Silverlight 中的 App.xaml.cs 中，我创建一个 IDataService 并在整个应用程序中使用它：

IDataService ds = ViewModelBase.IsDesignTimeStatic // from the MVVMLight toolkit
? (IDataService) new DesignTimeDataService()
: (IDataService) new DataService();

I've used the IDataService successfully to provide a testing and dummy data hook. The code that you have is an example of how you should use it. The DataItem is an example of an "Entity" or "DTO (Data Transfer Object)" that represents data from the database or service. If you're using WCF it would be the object that is generated when you do "Add Service Reference". The DataService class is a representation of the interface. This DataService class would have methods to call the real web service and do CRUD actions. You could also have a DesignTimeDataService: IDataService that has the same methods, but creates the data using a foreach in memory. You could then use IoC or other Dependency injection to inject the implementation at runtime.

In my App.xaml.cs in Silverlight, I create an IDataService and use that throughout my application:

IDataService ds = ViewModelBase.IsDesignTimeStatic // from the MVVMLight toolkit
? (IDataService) new DesignTimeDataService()
: (IDataService) new DataService();

回复收藏 0 原文