阅读下列说明和Visual Basic代码,将应填入(n)处的字句写在对应栏内。 [说明] 某小型家电超市开发了下面的程序,用以实现商品提货信息的汇总和输出功能。程序的运行界面如下图所示: 程序界面包含两个控件数组,分别是提货商品复选框控件数组Check1以及提货数量文本框控件数组Text1(相同下标的复选框和文本框相对应),提货清单的显示由List控件实现,按钮“打印清单”和“清除”分别名为Command1和Command2。 [Visual Basic代码] ’提货商品复选框的单击事件响应代码 Private Sub Check1_Click(Index As Integer) If Check1 (Index). Value = 1 Then (1). SetFocus End Sub ’按钮“打印清单”的单击事件响应代码 Private Sub Command1_Click() Dim i, n, price As Integer, sum As Long, title As String sum = 0 For i = O To 4 Select Case i Case 0: title ='电视机': price = 3580 Case 1: title ='微波炉': price = 660 Case 2: title ='电冰箱': price = 1850 Case 3: title ='DVD': price = 2880 Case 4: title ='空调': price = 2500 End Select If (2)= 1 And Textl(i). Text < > ' ' Then (3) title & Text1(i).Text & '台' n = n + Val(Textl(i)) sum =(4) End If Next i If sum < > 0 Then (3) '共:' & n &'台,' &'合计金额:'& sum &'元。' End If End Sub ’按钮“清除”的单击事件响应代码 Private Sub Command2_Click() (5) End Sub