如何将我的服务注册为全局服务或如何在我的场景中使用 MEF? [英] How to register my service as a global service or how can I use MEF in my scenario?

问题描述

我想创建自己的具有全球知名度的服务.为了实现这一点，我遵循了这个示例解决方案.

I would like to create my own service with global visibility. To implement that, I followed this sample solution.

一切顺利，我可以在一个类中调用我的服务，这个类继承自 Package 抽象类，方式如下:

Everything goes well, I can call my service within a class, which extends from the Package abstract class, in this way:

public class ClientPackage : Package
{
   private void GetGlobalServiceCallback(object sender, EventArgs args)
   {
      IMyGlobalService service = GetService(typeof(SMyGlobalService)) as IMyGlobalService;
   }
}

因为我在一个包裹中，所以我可以轻松地调用 GetService 并且我可以获得我的服务.但是如果我想从一个不扩展 Package 抽象类的类中获取我的服务呢?

Because I'm in a Package, I can easily call GetService and I can get my service. But what about if I want to get my service from a class, which is not extends the Package abstract class?

例如，我有一个类，它实现了一个 ITagger 接口.如果我想在这个类中获得一个服务，我必须这样使用Package.GetGlobalService()方法:

For example, I have a class, which implements an ITagger interface. If I want to get a service in this class, I have to use Package.GetGlobalService() method in this way:

var txtMgr = (IVsTextManager)Package.GetGlobalService(typeof(SVsTextManager));

我尝试使用 Package.GetGlobalServie() 获得我自己的服务，但我总是得到 null.链接的示例代码不包含解决我的问题的解决方案.

I tried to get my own service with the Package.GetGlobalServie(), but I always getting null. The linked sample code doesn't contain a soluiton for my problem.

我可能错过了什么，或者我有错误的场景来获得我的服务?

May I missed something or I have a wrong scenario to get my service?

好的，假设我必须使用 MEF 来获取我的服务，因为我无法使用 Package.GetGlobalService() 获取我的服务.

Okay, let's say I have to use MEF to get my service, because I can't get my service with Package.GetGlobalService().

我有一个包含 2 个项目的解决方案.一个是类库，它包含这样的接口:

I have a solution with 2 projects in it. One is a class library, which contains an interface like this:

public interface INamesAccessor
{
    IEnumerable<string> GetNames();
}

另一个项目是 VSPackage(参考第一个项目)，它也实现了我的界面:

The other project is the VSPackage (has a reference with the first project), which implements my interface as well:

[Export(typeof(INamesAccessor))]
public sealed class BitbucketExtensionPackage : Package, INamesAccessor
{
    private IEnumerable<string> _names { get; set; }

    public IEnumerable<string> GetNames()
    {
        return _names;
    }
}

假设用户单击工具"菜单下的给定菜单，逻辑会设置名称的值.直到 _names 为空.

Let's say that if the user clicks a given menu under the Tools menu, the logic set the value of the names. Until that the _names is empty.

我想在我的提供商处使用此 _names 列表的内容，例如:

I would like to use the content of this _names list at my provider, like:

[Export(typeof(ITaggerProvider))]
[ContentType("text")]
[TagType(typeof(CommentTag))]
internal sealed class CommentTaggerProvider : ITaggerProvider
{
    [Import]
    public INamesAccessor _namesAccessor { get; set; }

    public ITagger<T> CreateTagger<T>(ITextBuffer buffer) where T : ITag
    {
        if (buffer == null)
            throw new ArgumentNullException("buffer");

        return buffer.Properties.GetOrCreateSingletonProperty(() => new CommentTagger(buffer, _namesAccessor )) as ITagger<T>;
    }
}

我在这里得到了 namesAccessor，但每个字段都是空的，_names IEnumerable 也是.

I get the namesAccessor here, but every fields are null, the _names IEnumerable also.

当用户单击菜单按钮时，有没有办法强制 MEF 再次导入我的访问器?我做错了什么?

Is there a way to force the MEF to import my accessor again when the user click to the menu button? What did I wrong?

感谢您的回答！:)

推荐答案

您应该使用 MEF 为您的扩展组合服务；不是旧的基于 COM 的 ServiceProvider 的东西.

You should use MEF to composes services for your extensions; not the old COM-based ServiceProvider stuff.

将所有实际代码放在 MEF 导出的类中，然后使用 SComponentModel 服务从包类中调用它们.

Put all of your actual code in MEF-exported classes, then invoke them from the package class using the SComponentModel service.

有关更多信息，请参阅我的博客.

For more information, see my blog.

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