Private Sub Command1_Click()

    Dim i As Integer, S As String

    Dim str As String, ch As String

    str = Text1.Text

    List1.Clear

    For i = 1 To Len(str)

        ch =    ①    

        S = convert(ch)

        List1.AddItem ch & "==>" & S

    Next i

End Sub

Private Function convert(ch As String)  As String

    Dim m As Integer, k As Integer, n As Integer, i As Integer

    convert = ""

    n = Asc(ch)

    Do While n > 0

    ②   

        convert = m & convert

        If m = 1 Then

            k = k + 1

        End If

        n = n \ 2

    Loop

    For i = 1 To 7 - Len(convert)  '将字符的二进制代码补足7位

        convert = "0" & convert

    Next i

    If k Mod 2 = 0 Then

        convert =    ③    

    Else

        convert = "0" & convert

    End If

End Function

程序中划线处①的代码应为。

程序中划线处②的代码应为。

程序中划线处③的代码应为。