Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 ComboBox1.Items.Add("一碗湯麵") : ComboBox1.Items.Add("三國演義")'加入清單
 ComboBox1.Items.Add("小太陽") : ComboBox1.Items.Add("心靈雞湯")
 ComboBox1.Items.Add("人子") : ComboBox1.Items.Add("未央歌")
 ComboBox1.Items.Add("亂世佳人") : ComboBox1.Items.Add("哈利波特")
End Sub

 

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 If ListBox1.Items.Count < 3 And ComboBox1.Text <> "" Then '從書庫清單到借書清單
  ListBox1.Items.Add(ComboBox1.Text)
  ComboBox1.Items.Remove(ComboBox1.Text)
 End If
End Sub

 

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
 If ListBox1.Items.Count >=0 Then '從借書清單到書庫清單
  ListBox1.Items.Add(ComboBox1.Text)
  ComboBox1.Items.Remove(ComboBox1.Text)
  ComboBox1.Items.Add(ListBox1.Text)'與button1功能恰巧相反
  ListBox1.Items.Remove(ListBox1.Text)
 End If
End Sub