如何异步更新ICompletionSource中的完成结果？

Question

我正在尝试在Visual Studio中为Google Dart语言实现代码完成。我已经成功地在ICompletionSource like this中实现了一些硬编码的值

class CompletionSource : ICompletionSource
{
    CompletionSourceProvider provider;
    ITextBuffer buffer;
    ITextDocumentFactoryService textDocumentFactory;
    DartAnalysisService analysisService;

    public CompletionSource(CompletionSourceProvider provider, ITextBuffer buffer, ITextDocumentFactoryService textDocumentFactory, DartAnalysisService analysisService)
    {
        this.provider = provider;
        this.buffer = buffer;
        this.textDocumentFactory = textDocumentFactory;
        this.analysisService = analysisService;
    }

    public void AugmentCompletionSession(ICompletionSession session, IList<CompletionSet> completionSets)
    {
        var triggerPoint = session.GetTriggerPoint(buffer.CurrentSnapshot);
        if (triggerPoint == null)
            return;

        var applicableTo = buffer.CurrentSnapshot.CreateTrackingSpan(new SnapshotSpan(triggerPoint.Value, 1), SpanTrackingMode.EdgeInclusive);

        var completions = new ObservableCollection<Completion>();
        completions.Add(new Completion("Something1"));
        completions.Add(new Completion("Something2"));
        completions.Add(new Completion("Something3"));

        completionSets.Add(new CompletionSet("All", "All", applicableTo, completions, Enumerable.Empty<Completion>()));
    }

    public void Dispose()
    {
        GC.SuppressFinalize(true);
    }
}

这一切都运行得很好。然而，在实际的实现中，获取完成的操作很慢(它由另一个进程处理)，所以我需要能够稍后返回这些结果。

如果我同步完成所有工作，编辑器在请求期间挂起(这并不奇怪)。

文档相当糟糕。我尝试了所有的排序；包括在CompletionSet构造函数中使用两个IEnumerable<Completion>参数；在ObservableCollection<Completion>中插入值，在会话和CompletionSet上调用Recalculate()。

这是一个在1秒后将第二个值插入到完成列表中的实现。这不起作用；但对于任何想要尝试的人来说，这是一个起点：

    public void AugmentCompletionSession(ICompletionSession session, IList<CompletionSet> completionSets)
    {
        var triggerPoint = session.GetTriggerPoint(buffer.CurrentSnapshot);
        if (triggerPoint == null)
            return;

        ITextDocument doc;
        if (!textDocumentFactory.TryGetTextDocument(buffer, out doc))
            return;

        var applicableTo = buffer.CurrentSnapshot.CreateTrackingSpan(new SnapshotSpan(triggerPoint.Value, 1), SpanTrackingMode.EdgeInclusive);

        var completions = new ObservableCollection<Completion>();
        completions.Add(new Completion("Hard-coded..."));

        var completionSet = new CompletionSet("All", "All", applicableTo, Enumerable.Empty<Completion>(), completions);
        completionSets.Add(completionSet);

        Task.Run(async () =>
        {
            await Task.Delay(1000); // Wait 1s
            completions.Add(new Completion("Danny")); // This doesn't update the code-completion list; why not?
        });
    }

Answer 1

您可以在IIntellisenseController实现中异步触发完成本身，而不是异步更新完成源。当您检测到需要完成时，首先执行所需结果的后台计算，然后使用ICompletionBroker触发结果显示。