清除集合中的所有项目

清除 Collection 中所有物品的最简单方法是简单地用新的 Collection 替换它，让旧的物品超出范围：

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，如果对 Collection 有多个引用，则此方法仅为你分配的变量提供空的 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

在这种情况下，清除内容的最简单方法是循环遍历 Collection 中的项目数，并重复删除最低项：

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