清除集合中的所有專案

清除 Collection 中所有物品的最簡單方法是簡單地用新的 Collection 替換它，讓舊的物品超出範圍：

Public Sub Example()
    Dim foo As New Collection
    
    With foo
        .Add "One"
        .Add "Two"
        .Add "Three"
    End With
     
    Debug.Print foo.Count   'Prints 3
    Set foo = New Collection
    Debug.Print foo.Count   'Prints 0
End Sub

但是，如果對 Collection 有多個引用，則此方法僅為你分配的變數提供空的 Collection 。

Public Sub Example()
    Dim foo As New Collection
    Dim bar As Collection
    
    With foo
        .Add "One"
        .Add "Two"
        .Add "Three"
    End With
     
    Set bar = foo
    Set foo = New Collection
    
    Debug.Print foo.Count   'Prints 0
    Debug.Print bar.Count   'Prints 3
End Sub

在這種情況下，清除內容的最簡單方法是迴圈遍歷 Collection 中的專案數，並重復刪除最低項：

Public Sub ClearCollection(ByRef container As Collection)
    Dim index As Long
    For index = 1 To container.Count
        container.Remove 1
    Next
End Sub