此 C# 代码位于 .NET 4.5ComVisible程序集中：
C# 代码
[InterfaceType(ComInterfaceType.InterfaceIsDual)]
[Guid("22341223-9264-12AB-C1B4-B4F112014C31")]
public interface IComWithTask
{
void LongExecutionMethod(double x);
void LongExecutionMethodAsync(double x);
}
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
[Guid("23844123-9274-12CB-C1F4-B4F1521E4F33")]
public interface IComWithTaskEvents
{
void OnLongExecutionMethodComplete(double x);
}
[ClassInterface(ClassInterfaceType.None)]
[ComSourceInterfaces(typeof(IComWithTaskEvents))]
[Guid("E4F27AA4-1932-2196-1234-121CF2722C42")]
[ProgId("ComWithTask")]
public class ComWithTask : IComWithTask
{
[ComVisible(false)]
public delegate void LongExecutionMethodComplete(double x);
public event LongExecutionMethodComplete OnLongExecutionMethodComplete;
public void LongExecutionMethod(double x)
{
if (OnLongExecutionMethodComplete != null)
{
OnLongExecutionMethodComplete(x * x);
}
}
public void LongExecutionMethodAsync(double x)
{
Task.Factory.StartNew(state =>
{
var onLongExecutionMethodComplete = OnLongExecutionMethodComplete;
if (onLongExecutionMethodComplete != null)
{
onLongExecutionMethodComplete(x * x);
}
}, null);
}
}
从 Excel 2010 32bit VBA，我有以下行为：
VBA 代码
Private WithEvents oComWithTask As ComWithTask
Public Sub Class_Initialize()
Set oComWithTask = New ComWithTask
End Sub
Public Sub LongExecutionMethod()
' Works as expected
Call oComWithTask.LongExecutionMethod(2)
End Sub
Public Sub LongExecutionMethodAsync()
' Does NOT work!
Call oComWithTask.LongExecutionMethodAsync(3)
End Sub
Private Sub oComWithTask_OnLongExecutionMethodComplete(ByVal x As Double)
MsgBox x
End Sub
我知道我在调用 .NET 时正在旋转一个线程LongExecutionMethodAsync，并且我知道办公应用程序是单线程的。
我确实找到了关于以多线程方式从 .NET 调用 COM 组件的优秀文献，但找不到任何相反的资源，即 VBA 调用使用 COM 方法包装的多线程 .NET。
关于如何
LongExecutionMethodAsync使用多线程工作的任何想法，你能指出我关于这个主题的任何相关资源吗？另外，您对在 VBA 中触发异步事件有其他建议吗？