'功能： 将字节变量循环左移n位
'入口参数：MoveByte 需要移位的字节变量
' n 移动的位数
'返回值： 移位后的字节变量
Public Function ByteLeftMove(MoveByte As Byte, N As Integer) As Byte
Dim Intem As Byte '临时变量
Dim Intem1 As Byte '临时变量
Dim x As Integer, y As Integer
Intem1 = MoveByte
For x = 1 To N '移多少位就循环多少次
For y = 8 To 1 Step -1 '从第八位(左边第一位)开始循环左移
Select Case y
Case 8
'如果临时变量intem1的第八位是1,
If (Intem1 And &H80) = &H80 Then
'则将临时变量intem置1,
Intem = &H1
Else
Intem = &H0 '反之置0
End If
Case 7
'如果临时变量intem1的第七位是1,
If (Intem1 And &H40) = &H40 Then
'则将其第八位置1(其它位不变),
Intem1 = Intem1 Or &H80
Else
'反之将第八位置0(其它位不变)
Intem1 = Intem1 And &H7F
End If
Case 6
'操作与上面相同
If (Intem1 And &H20) = &H20 Then
Intem1 = Intem1 Or &H40
Else
Intem1 = Intem1 And &HBF
End If
Case 5
If (Intem1 And &H10) = &H10 Then
Intem1 = Intem1 Or &H20
Else
Intem1 = Intem1 And &HDF
End If
Case 4
If (Intem1 And &H8) = &H8 Then
Intem1 = Intem1 Or &H10
Else
Intem1 = Intem1 And &HEF
End If
Case 3
If (Intem1 And &H4) = &H4 Then
Intem1 = Intem1 Or &H8
Else
Intem1 = Intem1 And &HF7
End If
Case 2
If (Intem1 And &H2) = &H2 Then
Intem1 = Intem1 Or &H4
Else
