使用类的文本名称创建一个新对象 [英] Create a new object using the text name of the class

问题描述

是否可以通过使用类的文本名称将对象设置为类的新实例?

Is there a way to set an object to the new instance of a class by using the text name of the class?

我将拥有一个类库，根据其他变量，我想在运行时获取这些类之一.

I will have a library of classes, and depending on some other variable, I want to get one of these classes at runtime.

例如我有"CTest1"，"CTest2"，"CTest3"

E.g. I have "CTest1", "CTest2", "CTest3"

我将具有与以下类似的功能

I would have function similar to the below

Function GetTestClass(lngClassNo as long) as Object
  Dim strClassName as String    
  strClassName = "CTest" & CStr(lngClassNo)
  Set GetTestClass = New instance of class(strClassName)
End Function

推荐答案

VBA中没有任何反映，因此我认为这是不可能的.恐怕您必须执行以下操作:

There's no reflection in VBA, so I don't think this is possible. You'd have to do something like the following I'm afraid:

Function GetTestClass(lngClassNo as long) as Object

    Select Case lngClassNo
    Case 1
        Set GetTestClass = New CTest1
    Case 2
        Set GetTestClass = New CTest2
    ...

    End Select

End Function

除非您的CTest类是在COM DLL中定义的，否则可以使用CreateObject语句.但是，您将需要使用VB6创建这样的DLL，而不能在Excel，Access等中创建DLL.

Unless that is your CTest classes are defined in a COM DLL, in which case you could use the CreateObject statement. You would need to use VB6 to create such a DLL though, you can't create DLLs in Excel, Access, etc.

Function GetTestClass(lngClassNo as long) as Object

    Set GetTestClass = CreateObject("MyDll.CTest" & lngClassNo)

End Function

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