Question

VBIDE API公开了奇妙的神秘_dispVBComponentsEvents界面（以及其他界面），看起来像我可以用来捕捉VBE中各种有趣事件的东西。

所以我在一个类中实现了接口，该类打算捕获事件并为我的应用程序的其余部分引发一个“正常”.net事件，如下所示：

public class VBComponentsEventDispatcher : _dispVBComponentsEvents
{
    public event EventHandler<DispatcherEventArgs<VBComponent>> ComponentAdded;
    public void ItemAdded(VBComponent VBComponent)
    {
        OnDispatch(ComponentAdded, VBComponent);
    }

    public event EventHandler<DispatcherEventArgs<VBComponent>> ComponentRemoved;
    public void ItemRemoved(VBComponent VBComponent)
    {
        OnDispatch(ComponentRemoved, VBComponent);
    }

    public event EventHandler<DispatcherRenamedEventArgs<VBComponent>> ComponentRenamed;
    public void ItemRenamed(VBComponent VBComponent, string OldName)
    {
        var handler = ComponentRenamed;
        if (handler != null)
        {
            handler.Invoke(this, new DispatcherRenamedEventArgs<VBComponent>(VBComponent, OldName));
        }
    }

    public event EventHandler<DispatcherEventArgs<VBComponent>> ComponentSelected;
    public void ItemSelected(VBComponent VBComponent)
    {
        OnDispatch(ComponentSelected, VBComponent);
    }

    public event EventHandler<DispatcherEventArgs<VBComponent>> ComponentActivated;
    public void ItemActivated(VBComponent VBComponent)
    {
        OnDispatch(ComponentActivated, VBComponent);
    }

    public event EventHandler<DispatcherEventArgs<VBComponent>> ComponentReloaded;
    public void ItemReloaded(VBComponent VBComponent)
    {
        OnDispatch(ComponentReloaded, VBComponent);
    }

    private void OnDispatch(EventHandler<DispatcherEventArgs<VBComponent>> dispatched, VBComponent component)
    {
        var handler = dispatched;
        if (handler != null)
        {
            handler.Invoke(this, new DispatcherEventArgs<VBComponent>(component));
        }
    }
}

我希望能像这样使用这个类：

var componentsEvents = new VBComponentsEventDispatcher();
componentsEvents.ComponentAdded += componentsEvents_ComponentAdded;
componentsEvents.ComponentActivated += componentsEvents_ComponentActivated;
//...

void componentsEvents_ComponentAdded(object sender, DispatcherEventArgs<VBComponent> e)
{
    Debug.WriteLine(string.Format("Component '{0}' was added.", e.Item.Name));
}

void componentsEvents_ComponentActivated(object sender, DispatcherEventArgs<VBComponent> e)
{
    Debug.WriteLine(string.Format("Component '{0}' was activated.", e.Item.Name));
}

但它不起作用，我没有调试输出，并且没有命中断点。显然我不知道我在做什么。 MSDN在这个问题上完全没用，找到关于这个的文档比找到亨利八世的第三任妻子的婚前姓更难。

我做错了什么，如何让它发挥作用？我是在正确的轨道上吗？

Answer 1

我是在正确的轨道上吗？

是。您在事件接收器中拥有的内容 - 您缺少一些代码来使用COM服务器注册接收器。

VBProjects和VBComponents接口实现（某处非常深）IConnectionPointContainer接口 - 您需要使用它来收集IConnectionPoint个实例。要取消注册接收器，您需要一个数据结构来记住注册步骤为您提供的int cookie。

这是一个粗略的例子 - 假设您有一个App类，其中包含以下字段：

private readonly IConnectionPoint _projectsEventsConnectionPoint;
private readonly int _projectsEventsCookie;

private readonly IDictionary<VBComponents, Tuple<IConnectionPoint, int>>  _componentsEventsConnectionPoints = 
    new Dictionary<VBComponents, Tuple<IConnectionPoint, int>>();

在构造函数中的某处，您将使用IConnectionPoint.Advise注册接收器，并注册自定义事件处理程序：

var sink = new VBProjectsEventsSink();
var connectionPointContainer = (IConnectionPointContainer)_vbe.VBProjects;
Guid interfaceId = typeof (_dispVBProjectsEvents).GUID;
connectionPointContainer.FindConnectionPoint(ref interfaceId, out _projectsEventsConnectionPoint);

sink.ProjectAdded += sink_ProjectAdded;
sink.ProjectRemoved += sink_ProjectRemoved;
sink.ProjectActivated += sink_ProjectActivated;
sink.ProjectRenamed += sink_ProjectRenamed;

_projectsEventsConnectionPoint.Advise(sink, out _projectsEventsCookie);

然后，当添加项目时，您将使用IConnectionPoint.Advise为每个组件注册一个接收器，然后您可以注册自定义事件处理程序，并在您的字典中添加一个条目：

void sink_ProjectAdded(object sender, DispatcherEventArgs<VBProject> e)
{
    var connectionPointContainer = (IConnectionPointContainer)e.Item.VBComponents;
    Guid interfaceId = typeof(_dispVBComponentsEvents).GUID;

    IConnectionPoint connectionPoint;
    connectionPointContainer.FindConnectionPoint(ref interfaceId, out connectionPoint);

    var sink = new VBComponentsEventsSink();
    sink.ComponentActivated += sink_ComponentActivated;
    sink.ComponentAdded += sink_ComponentAdded;
    sink.ComponentReloaded += sink_ComponentReloaded;
    sink.ComponentRemoved += sink_ComponentRemoved;
    sink.ComponentRenamed += sink_ComponentRenamed;
    sink.ComponentSelected += sink_ComponentSelected;

    int cookie;
    connectionPoint.Advise(sink, out cookie);

    _componentsEventsConnectionPoints.Add(e.Item.VBComponents, Tuple.Create(connectionPoint, cookie));
}

删除项目后，使用IConnectionPoint.Unadvise取消注册接收器，并删除字典条目：

void sink_ProjectRemoved(object sender, DispatcherEventArgs<VBProject> e)
{
    Tuple<IConnectionPoint, int> value;
    if (_componentsEventsConnectionPoints.TryGetValue(e.Item.VBComponents, out value))
    {
        value.Item1.Unadvise(value.Item2);
        _componentsEventsConnectionPoints.Remove(e.Item.VBComponents);
    }
}

然后你可以在你的处理程序中运行你想要的任何代码：

void sink_ComponentAdded(object sender, DispatcherEventArgs<VBComponent> e)
{
    _parser.State.OnParseRequested(e.Item);
}

如果您的Dispose课程中有App方法，那么这将是清理任何遗留物的好地方：

public void Dispose()
{
    _projectsEventsConnectionPoint.Unadvise(_projectsEventsCookie);
    foreach (var item in _componentsEventsConnectionPoints)
    {
        item.Value.Item1.Unadvise(item.Value.Item2);
    }
}

Answer 2

System.Runtime.InteropServices命名空间公开了一个静态ComEventsHelper类，用于将托管代理连接到非托管调度源。这基本上与other answer完全相同，但连接点在运行时可调用包装器中处理，而不必从调用代码显式管理（从而使其更加健壮）。我怀疑这就是PIA在内部处理源接口的方式（对问题Microsoft.Vbe.Interop进行反编译已经足够严重，以至于很难说明。）

在这种情况下，由于某些不可思议的原因，所讨论的接口未被声明为源接口，因此PIA构建没有在运行时包装器中连接事件处理程序。所以...你可以在包装器类中手动连接处理程序并将它们作为包装事件转发，但仍然需要处理连接点到RCW的繁重（和线程安全管理）。请注意，您需要来自引用类型库的2条信息 - _dispVBComponentsEvents界面的guid以及您有兴趣收听的非托管事件的DispId ：

private static readonly Guid VBComponentsEventsGuid = new Guid("0002E116-0000-0000-C000-000000000046");

private enum ComponentEventDispId
{
    ItemAdded = 1,
    ItemRemoved = 2,
    ItemRenamed = 3,
    ItemSelected = 4,
    ItemActivated = 5,
    ItemReloaded = 6
}

然后，将它们连接到类包装器的ctor（为简洁起见只显示一个）......

private delegate void ItemAddedDelegate(VB.VBComponent vbComponent);
private readonly ItemAddedDelegate _componentAdded;

public VBComponents(VB.VBComponents target) 
{
    _target = target;
    _componentAdded = OnComponentAdded;
    ComEventsHelper.Combine(_target, 
                            VBComponentsEventsGuid, 
                            (int)ComponentEventDispId.ItemAdded, 
                           _componentAdded);
}

...并转发事件：

public event EventHandler<DispatcherEventArgs<IVBComponent>> ComponentAdded;
private void OnComponentAdded(VB.VBComponent vbComponent)
{
    OnDispatch(ComponentAdded, VBComponent);
}

private void OnDispatch(EventHandler<DispatcherEventArgs<IVBComponent>> dispatched, VB.VBComponent component)
{
    var handler = dispatched;
    if (handler != null)
    {
        handler.Invoke(this, new DispatcherEventArgs<IVBComponent>(new VBComponent(component)));
    }
}

完成后，请致电ComEventsHelper.Remove取消注册代表：

ComEventsHelper.Remove(_target, 
                       VBComponentsEventsGuid,
                       (int)ComponentEventDispId.ItemAdded,
                       _componentAdded);

上面的示例根据问题使用了一个包装类，但是如果您需要在处理COM事件或将其传递给其他侦听器之前将其他功能附加到COM事件，则可以从任何地方使用相同的方法。

如何连接COM事件调度程序？

2 个答案: