excel - VBA中的if-then语句

Question

我目前正在编写两组非常相似的 if-else 语句。他们基本上比较三个下拉菜单，并确保用户没有放下两个匹配的偏好。例如:

cbo_fac1 - Kitchen    
cbo_fac2 - Kitchen   
cbo_fac3 - Lounge

这将返回一条错误消息，因为 cbo_fac1 和 cbo_fac2 配对。但是有一个我正在努力实现的特殊情况。下拉案例之一是无偏好。

cbo_fac1 - Kitchen    
cbo_fac2 - No preference
cbo_fac3 - No preference

cbo_fac1 - No preference    
cbo_fac2 - No preference
cbo_fac3 - No preference

任何情况下都不允许匹配任何偏好选择。我该如何实现呢？这是我到目前为止使用的代码:

If cbo_fac1.Value = cbo_fac2.Value Then
    MsgBox ("Facilities preference 1 and facilities preference 2 cannot be the same. Please select another option for facilities preference 2, if you have none then select 'No preference'")
    Exit Sub
End If

If cbo_fac1.Value = cbo_fac3.Value Then
    MsgBox ("Facilities preference 1 and facilities preference 3 cannot be the same. Please select another option for facilities preference 3, if you have none then select 'No preference'")
    Exit Sub
End If

If cbo_fac2.Value = cbo_fac3.Value Then
    MsgBox ("Facilities preference 2 and facilities preference 3 cannot be the same. Please select another option for facilities preference 3, if you have none then select 'No preference'")
    Exit Sub
End If

Answer 1

如果你想把它写成一个巨大的 if 语句，应该这样做:

If (cbo_fac1.Value <> cbo_fac2.Value Or cbo_fac1.Value = "No Preference") And _
   (cbo_fac2.Value <> cbo_fac3.Value Or cbo_fac2.Value = "No Preference") And _
   (cbo_fac1.Value <> cbo_fac3.Value Or cbo_fac3.Value = "No Preference") Then
     'Input is fine
else
     exit sub

End If

编辑:

只是因为这是相反的方式，可能带有一个 msgbox:

If (cbo_fac1.value = cbo_fac2.value AND cbo_fac1.value <> "No Preference") OR _
   (cbo_fac2.value = cbo_fac3.value AND cbo_fac2.value <> "No Preference") OR _
   (cbo_fac1.value = cbo_fac3.value AND cbo_fac3.value <> "No Preference") then

   Msgbox "No two facilities can be the same. Please select another option " & _
          "for facilities preference, if you have none then select 'No preference'"
   exit sub
else
   'input is fine
end if