修改VB程序:选中列表框中相应项,在文本框中输入准考证后四位,单击“确定”按钮,如输入错误则弹出对话框“输入错误,请重新输入,系统将5秒后正常工作”,然后列表框、文本框、确认按钮不可用,并显示进度条;5秒后,进度条不可见,清空文本框,列表框获得焦点并选中第一项,若输入正确,则弹出对话框“输入正确”,并退出程序,点按“退出”按钮则退出程序。程序运行效果如下: Dim n% Private Sub Command1_Click() If Text1.Text <> "" ____1____ Right(List1.Text, 4) = Text1.Text Then MsgBox "输入正确", 48: End Else MsgBox "输入错误,请重新输入,系统将5秒后正常工作" Text1.Enabled = ___2___ Command1.Enabled = ___2___ List1.Enabled = ___2___ Timer1.Enabled = ___3___ n = 0 Label2(n).Visible = True End If End Sub Private Sub Command2_Click() ___4___ End Sub Private Sub Timer1_Timer() n = n + 1 If ___5___ Then Label2(n).Visible = True Else For i = 0 To 4 Label2(i).Visible = False Next i Text1.Enabled = True Command1.Enabled = True List1.Enabled = True List1.ListIndex = 0 Text1.Text = ___6___ Timer1.Enabled = ___7___ End If End Sub