我有一个遗留的VB6组件，使用tlbimp.exe将其导入到VS中，生成我的互操作程序集。VB6组件定义了一个事件，允许我在VB6中传递消息。
Public Event Message(ByVal iMsg As Variant, oCancel As Variant)
我希望能够在我的C#程序中触发此事件，但它被导入为事件而不是委托或其他有用的东西。因此，我只能监听，但永远无法触发。有人知道如何触发包含在VB6中的事件吗？C#事件看起来像：
[TypeLibType(16)]
[ComVisible(false)]
public interface __MyObj_Event
{
event __MyObj_MessageEventHandler Message;
}
很遗憾，我无法更改VB6代码。谢谢。
MyObj legacyComObject = new MyObj();
// The following code assumes other COM objects have already subscribed to the
// MyObj class's Message event at this point.
//
// NOTE: VB6 objects have two hidden interfaces for classes that raise events:
//
// _MyObj (with one underscore): The default interface.
// __MyObj (with two underscores): The event interface.
//
// We want the second interface, because it gives us a delegate
// that we can use to raise the event.
// The ComEventUtils.GetEventSinks<T> method is a convenience method
// that returns all the objects listening to events from the legacy COM object.
// set up the params for the event
string messageData = "Hello, world!";
bool cancel = false;
// raise the event by invoking the event delegate for each connected object...
foreach(__MyObj sink in ComEventUtils.GetEventSinks<__MyObj>(legacyComObject))
{
// raise the event via the event delegate
sink.Message(messageData, ref cancel);
if(cancel == true)
{
// do cancel processing (just an example)
break;
}
}
ComEventUtils 类的代码（以及帮助类 SafeIntPtr，因为我很谨慎，想要一种好的方式来处理与 COM 相关的代码所需的 IntPtr）：
免责声明：我没有彻底测试下面的代码。在一些地方，代码执行手动内存管理，因此可能会在您的代码中引入内存泄漏的可能性。此外，我没有添加错误处理到代码中，因为这只是一个示例。请小心使用。using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using COM = System.Runtime.InteropServices.ComTypes;
namespace YourNamespaceHere
{
/// <summary>
/// A utility class for dealing with COM events.
/// Needs error-handling and could potentially be refactored
/// into a regular class. Also, I haven't extensively tested this code;
/// there may be a memory leak somewhere due to the rather
/// low-level stuff going on in the class, but I think I covered everything.
/// </summary>
public static class ComEventUtils
{
/// <summary>
/// Get a list of all objects implementing an event sink interface T
/// that are listening for events on a specified COM object.
/// </summary>
/// <typeparam name="T">The event sink interface.</typeparam>
/// <param name="comObject">The COM object whose event sinks you want to retrieve.</param>
/// <returns>A List of objects that implement the given event sink interface and which
/// are actively listening for events from the specified COM object.</returns>
public static List<T> GetEventSinks<T>(object comObject)
{
List<T> sinks = new List<T>();
List<COM.IConnectionPoint> connectionPoints = GetConnectionPoints(comObject);
// Loop through the source object's connection points,
// find the objects that are listening for events at each connection point,
// and add the objects we are interested in to the list.
foreach(COM.IConnectionPoint connectionPoint in connectionPoints)
{
List<COM.CONNECTDATA> connections = GetConnectionData(connectionPoint);
foreach (COM.CONNECTDATA connection in connections)
{
object candidate = connection.pUnk;
// I tried to avoid relying on try/catch for this
// part, but candidate.GetType().GetInterfaces() kept
// returning an empty array.
try
{
sinks.Add((T)candidate);
}
catch { }
}
// Need to release the interface pointer in each CONNECTDATA instance
// because GetConnectionData implicitly AddRef's it.
foreach (COM.CONNECTDATA connection in connections)
{
Marshal.ReleaseComObject(connection.pUnk);
}
}
return sinks;
}
/// <summary>
/// Get all the event connection points for a given COM object.
/// </summary>
/// <param name="comObject">A COM object that raises events.</param>
/// <returns>A List of IConnectionPoint instances for the COM object.</returns>
private static List<COM.IConnectionPoint> GetConnectionPoints(object comObject)
{
COM.IConnectionPointContainer connectionPointContainer = (COM.IConnectionPointContainer)comObject;
COM.IEnumConnectionPoints enumConnectionPoints;
COM.IConnectionPoint[] oneConnectionPoint = new COM.IConnectionPoint[1];
List<COM.IConnectionPoint> connectionPoints = new List<COM.IConnectionPoint>();
connectionPointContainer.EnumConnectionPoints(out enumConnectionPoints);
enumConnectionPoints.Reset();
int fetchCount = 0;
SafeIntPtr pFetchCount = new SafeIntPtr();
do
{
if (0 != enumConnectionPoints.Next(1, oneConnectionPoint, pFetchCount.ToIntPtr()))
{
break;
}
fetchCount = pFetchCount.Value;
if (fetchCount > 0)
connectionPoints.Add(oneConnectionPoint[0]);
} while (fetchCount > 0);
pFetchCount.Dispose();
return connectionPoints;
}
/// <summary>
/// Returns a list of CONNECTDATA instances representing the current
/// event sink connections to the given IConnectionPoint.
/// </summary>
/// <param name="connectionPoint">The IConnectionPoint to return connection data for.</param>
/// <returns>A List of CONNECTDATA instances representing all the current event sink connections to the
/// given connection point.</returns>
private static List<COM.CONNECTDATA> GetConnectionData(COM.IConnectionPoint connectionPoint)
{
COM.IEnumConnections enumConnections;
COM.CONNECTDATA[] oneConnectData = new COM.CONNECTDATA[1];
List<COM.CONNECTDATA> connectDataObjects = new List<COM.CONNECTDATA>();
connectionPoint.EnumConnections(out enumConnections);
enumConnections.Reset();
int fetchCount = 0;
SafeIntPtr pFetchCount = new SafeIntPtr();
do
{
if (0 != enumConnections.Next(1, oneConnectData, pFetchCount.ToIntPtr()))
{
break;
}
fetchCount = pFetchCount.Value;
if (fetchCount > 0)
connectDataObjects.Add(oneConnectData[0]);
} while (fetchCount > 0);
pFetchCount.Dispose();
return connectDataObjects;
}
} //end class ComEventUtils
/// <summary>
/// A simple wrapper class around an IntPtr that
/// manages its own memory.
/// </summary>
public class SafeIntPtr : IDisposable
{
private bool _disposed = false;
private IntPtr _pInt = IntPtr.Zero;
/// <summary>
/// Allocates storage for an int and assigns it to this pointer.
/// The pointed-to value defaults to 0.
/// </summary>
public SafeIntPtr()
: this(0)
{
//
}
/// <summary>
/// Allocates storage for an int, assigns it to this pointer,
/// and initializes the pointed-to memory to known value.
/// <param name="value">The value this that this <tt>SafeIntPtr</tt> points to initially.</param>
/// </summary>
public SafeIntPtr(int value)
{
_pInt = Marshal.AllocHGlobal(sizeof(int));
this.Value = value;
}
/// <summary>
/// Gets or sets the value this pointer is pointing to.
/// </summary>
public int Value
{
get
{
if (_disposed)
throw new InvalidOperationException("This pointer has been disposed.");
return Marshal.ReadInt32(_pInt);
}
set
{
if (_disposed)
throw new InvalidOperationException("This pointer has been disposed.");
Marshal.WriteInt32(_pInt, Value);
}
}
/// <summary>
/// Returns an IntPtr representation of this SafeIntPtr.
/// </summary>
/// <returns></returns>
public IntPtr ToIntPtr()
{
return _pInt;
}
/// <summary>
/// Deallocates the memory for this pointer.
/// </summary>
public void Dispose()
{
if (!_disposed)
{
Marshal.FreeHGlobal(_pInt);
_disposed = true;
}
}
~SafeIntPtr()
{
if (!_disposed)
Dispose();
}
} //end class SafeIntPtr
} //end namespace YourNamespaceHere
Option Explicit
Private FText As String
Public Event OnChange(ByVal Text As String)
'This exposes the raising the event
Private Sub Change(ByVal Text As String)
RaiseEvent OnChange(Text)
End Sub
Public Property Get Text() As String
Text = FText
End Property
Public Property Let Text(ByVal Value As String)
FText = Value
Call Change(Value)
End Property
很抱歉要给您带来不好的消息。