Excel VBA中：特殊类型 - 函数作为函数的参数 [英] excel vba: Special Types - Functions as Arguments of Functions
问题描述
有没有特殊类型在VBA函数。这是我很难看到如何作为参数在Excel VBA中添加函数的功能。
There is no special type for functions in VBA. It is hard for me to see how to add functions as arguments to functions in Excel VBA.
我试图做到的是这样的：
What I am trying to accomplish is something like this:
function f(g as function, x as string) as string
f = g(x)
end function
目前，我有一组小函数所有重复自己，但有一个调用特定的功能。
Currently, I have a group of little functions all repeating themselves but with one call to a specific function.
推荐答案
从code，函数g接受一个字符串参数，并返回一个字符串。我建议你创建一个名为IStringFunction类模块作为一个接口的定义，所有功能都支持，这样的：
From your code, function g takes a string parameter and returns a string. I suggest you create a class module called IStringFunction to act as the definition of an interface that all functions will support, thus:
类模块：IStringFunction
Public Function Evaluate(ByVal s As String) As String
End Function
然后，创建一对夫妇实现此接口的功能，例如：
Then, create a couple of example functions implementing this interface:
类模块：HelloStringFunction
Implements IStringFunction
Public Function IStringFunction_Evaluate(ByVal s As String) As String
IStringFunction_Evaluate = "hello " & s
End Function
类模块：GoodbyeStringFunction
Implements IStringFunction
Public Function IStringFunction_Evaluate(ByVal s As String) As String
IStringFunction_Evaluate = "goodbye " & s
End Function
......终于，一些测试code行使的功能：
...and finally, some test code to exercise the functions:
（标准）模块：测试
Sub Test()
Dim oHello As New HelloStringFunction
Dim oGoodbye As New GoodbyeStringFunction
MsgBox Evaluate(oHello, "gary")
MsgBox Evaluate(oGoodbye, "gary")
End Sub
Private Function Evaluate(ByVal f As IStringFunction, ByVal arg As String) As String
Evaluate = f.Evaluate(arg)
End Function
需要注意的是实现该接口的类必须有一个名为＆LT方法;接口＆GT; _＆lt;方法＆GT; 在上面的例子中，不只是＆LT ;方法＆gt; 如你所期望
Note that the class implementing the interface must have methods named <Interface>_<Method> as in the example above, not just <Method> as you'd expect.
下载href=\"https://dl.dropbox.com/u/6194904/2012/demo%20functions%20as%20arguments%20of%20functions.xlsm\" rel=\"nofollow\">简单的演示<
Download the simple demo or intermediate demo here
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