VBA自定義集合對象

Question

我一直在嘗試學習如何在Excel VBA中創建自定義集合，並在MSDN上找到這段代碼。雖然我理解它的大部分，誰能告訴我最後的代碼Set Add = empNew在做什麼？我不明白這是評論。謝謝！

' Methods of the Employees collection class. 
Public Function Add(ByVal Name As String, _ 
ByVal Salary As Double) As Employee 
    Dim empNew As New Employee 
    Static intEmpNum As Integer 
    ' Using With makes your code faster and more 
    ' concise (.ID vs. empNew.ID). 
    With empNew 
     ' Generate a unique ID for the new employee. 
     intEmpNum = intEmpNum + 1 
     .ID = "E" & Format$(intEmpNum, "00000") 
     .Name = Name 
     .Salary = Salary 
     ' Add the Employee object reference to the 
     ' collection, using the ID property as the key. 
     mcolEmployees.Add empNew, .ID 
    End With 
    ' Return a reference to the new Employee. 
    Set Add = empNew 
End Function 

Answer 1

你會發現，Add是Function的名稱。通過發佈Set Add = newEmp您的代碼聲明該函數的return value（或此對象，在此例中）是新創建的員工對象newEmp。這意味着該函數會將變量newEmp傳回給其調用者。

說你有一些過程調用你的函數，你就可以做到這一點：

Sub listEmployees 
    Dim e As Employee 

    ' Create a new employee, and assign the variable e to point to this object 
    Set e = Add("John", 1000) ' Notice that the only reason we use "add" here is because it is the name of the function you provided 

    ' e is now an Employee object, after being created in the line above, meaning we can access whatever properties is defined for it. The function Add lists some properties, so we can use those as examples. 
    Debug.Print e.Name 
    Debug.Print e.Salary 
    Debug.Print e.ID 
End Sub 

Answer 2

首先，您需要定義您所創建的新Type，所以把下面的代碼之上你的模塊：

Public Type Employee 
    id As String 
    Name As String 
    Salary As Long 
End Type 

然後，你Public Function Add，更改爲Dim empNew As Employee內。 不知道你爲什麼需要下面這行：mcolEmployees.Add empNew, .id ??

和最後一行修改爲Add = empNew。

然後，當我從下面的子測試這個功能：

Sub testEmp() 

Dim s As Employee 

s = Add("Shai", 50000) 

End Sub 

我在即時窗口中獲得s以下值：

s.id = E00001 
s.Name = "Shai" 
s.Salary = 50000 

我希望這是你在何意您的帖子。