如何在IWpfTextView扩展中获取活动VS2019

Question

我正在尝试在C#扩展中获得active IWpfTextView编辑器。我使用一个小型的MEF服务将视图注入到VSAsyncPackage中。但它不是很可靠--有时注入的视图是错误的(例如从另一个视图)或缺失。以下是服务：

public interface IActiveViewAccessor
{
    IWpfTextView? ActiveView { get; }
}

[Export(typeof(IWpfTextViewConnectionListener))]
[Export(typeof(IActiveViewAccessor))]
[ContentType("text")]
[TextViewRole(PredefinedTextViewRoles.Document)]
internal sealed class ActiveViewConnectionListener : IWpfTextViewConnectionListener, IActiveViewAccessor
    {
    public IWpfTextView? ActiveView { get; private set; }

    public void SubjectBuffersConnected(IWpfTextView textView, ConnectionReason reason, Collection<ITextBuffer> subjectBuffers)
    {
        this.ActiveView = textView;
    }

    public void SubjectBuffersDisconnected(IWpfTextView textView, ConnectionReason reason, Collection<ITextBuffer> subjectBuffers)
    {
        this.ActiveView = null;
    }
}

此服务被注入VSPackage，如下所示：

this.viewAccessor = this.exportProvider.GetExportedValue<IActiveViewAccessor>();

它被用作：

var view = this.viewAccessor?.ActiveView;

是否有更好和更稳定的方法在异步IWpfTextView中获取VSPackage？

到目前为止，这里有一些相关的问题，但并不完全符合我的预期：

1. 如何从命令VisualStudioExtension2017 ( 2017 )获取IWpfTextView
2. 怎样才能得到IWpfTextView for EnvDte.ActiveDocument？(2013年)
3. 访问Visual扩展中的当前代码窗格(2012)

Answer 1

经过一些调试和探索，我得出结论，我的最初方法非常幼稚。因为在简单的情况下，IWpfTextViewConnectionListener在每个编辑器窗口只触发一次，而且在已经连接的视图之间切换时不会触发。

在对其进行实验并偷偷进入VsVim > VsAdapter.cs之后，我将IActiveViewAccessor更改为：

public interface IActiveViewAccessor
{
    IWpfTextView? ActiveView { get; }
}

[Export(typeof(IActiveViewAccessor))]
internal sealed class ActiveViewAccessor : IActiveViewAccessor
{
    private readonly SVsServiceProvider serviceProvider;
    private readonly IVsEditorAdaptersFactoryService editorAdaptersFactoryService;

    [ImportingConstructor]
    public ActiveViewAccessor(
        SVsServiceProvider vsServiceProvider,
        IVsEditorAdaptersFactoryService editorAdaptersFactoryService)
    {
        this.serviceProvider = vsServiceProvider;
        this.editorAdaptersFactoryService = editorAdaptersFactoryService;
    }

    public IWpfTextView? ActiveView
    {
        get
        {
            IVsTextManager2 textManager =
                serviceProvider.GetService<SVsTextManager, IVsTextManager2>();

            if (textManager == null)
            {
                return null;
            }

            int hr = textManager.GetActiveView2(
                fMustHaveFocus: 1,
                pBuffer: null,
                grfIncludeViewFrameType: (uint)_VIEWFRAMETYPE.vftCodeWindow,
                ppView: out IVsTextView vsTextView);

            if (ErrorHandler.Failed(hr))
            {
                return null;
            }

            return editorAdaptersFactoryService.GetWpfTextView(vsTextView);
        }
    }
}