列表框没有完全删除项目

Listbox is not completely removing items

我有一个表单,可以将选中的列表框中的选定项目存储到另一个表单的列表框中。

'Form2
 Public Sub New(ByVal Citems As List(Of String), ByVal Citems2 As List(Of String))
    InitializeComponent()
    ListBox1.Items.AddRange(Citems.ToArray)
    ListBox2.Items.AddRange(Citems2.ToArray)


 Private Sub Cancel_Click(sender As Object, e As EventArgs) Handles Button2.Click 
'Cancel the form and returns to Form 1

    ListBox1.Items.Clear()
    ListBox1.Refresh()
    ListBox2.Items.Clear()
    ListBox2.Refresh()
    Me.Close()
End Sub

'Form 1
 Dim Citems As New List(Of String)
Dim Citems2 As New List(Of String)


Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
    For Each I As String In CheckedListBox1.CheckedItems
        Citems.Add(I)
    Next

    For Each I As String In CheckedListBox2.CheckedItems
        Citems2.Add(I)
    Next

    Dim SecondForm As New Form2(Citems, Citems2)
    SecondForm.Show()

这是我拥有的用于清除列表框并关闭表单的代码。问题是当它再次打开时,先前选择的项目仍在列表框中。如何在不完全关闭应用程序的情况下清除数据?

这个有效:

 Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click

 Citems.Clear()
For Each I As String In CheckedListBox1.CheckedItems
        Citems.Add(I)
    Next
Citems2.Clear()
    For Each I As String In CheckedListBox2.CheckedItems
        Citems2.Add(I)

    Next

在添加之前清除列表。感谢您的帮助。