如何在 VS2019 扩展（MEF）中激活 IWpfTextView

Question

我正在尝试在 VS2019 扩展中获取活动的 C# 编辑器 IWpfTextView。我正在使用小型 MEF 服务将视图注入 VSAsyncPackage。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）或丢失。这是服务：

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;
    }
}

此服务被注入到 VSPackage 中：

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

它被用作：

var view = this.viewAccessor?.ActiveView;

有没有更好更稳定的方式在异步VSPackage中获取IWpfTextView？

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：

How can I get IWpfTextView for EnvDte.ActiveDocument? (2013)
Access current code pane in Visual Studio Extension (2012)

Answer 1

经过一番调试和探索，我得出结论，我最初的做法非常幼稚。因为在简单情况下 IWpfTextViewConnectionListener 每个编辑器 window 只触发一次，并且在已连接的视图之间切换时不会触发。

在尝试并潜入 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);
        }
    }
}

如何在 VS2019 扩展（MEF）中激活 IWpfTextView

How to get active IWpfTextView in VS2019 extension (MEF)

c#

mef

visual-studio-extensions

visual-studio-2019