Question

我正在VBA中创建一个项目来自动处理异步准多线程（满口，抱歉）。这围绕创建和运行Implements某个接口的类的多个副本，并在异步任务完成时引发一些已知事件。接口类似于this example

我的程序调用类来执行它的代码，并监听引发的事件，这一切都正常。现在我的最后一项任务是获取Implements适当接口的任何给定类，并使多个副本设置为并行运行。

如何制作传递给例程的类的副本？

如何获取课程参考并制作多个New版本？

或者在代码中，我的每个线程类（处理传递的异步类的类）都有一个Worker属性来保存它们的任务。

Private workerObject As IWorker
Public Property Set Worker(workObj As IWorker) 'pass unknown class with IWorker interface
    'What goes here?
    Set workerObject = workObj
    'This won't work as then every thread points to the same worker
    'I want something to create a New one, like
    Set workerObject = New ClassOf(workObj)
    'But of course that doesn't work
End Property

Answer 1

您需要检查可能的类型并采取相应措施：

Dim workerObject As IWorker

If TypeOf workObj Is ImplementingClass1 Then
    Set workerObject = New ImplementingClass1

ElseIf TypeOf workObj Is ImplementingClass2 Then
    Set workerObject = New ImplementingClass2

End If

或者，您可以在界面中添加工厂方法：

Public Function CreateNew() As IWorker: End Function

在课程中实施：

Public Function IWorker_CreateNew() As IWorker
    Set IWorker_CreateNew = New ImplementingClass1
End Function

然后：

Set workerObject = workObj.IWorker_CreateNew()

创建作为参数

1 个答案: