Excel UDF - 獲得價值！錯誤，不知道爲什麼

Question

在週五的一些好的建議，這幫助我修復我的VBA代碼之後，我想我會試着用一個類似的用戶定義的函數。這裏的想法是採取值的列表和（可選的）表引用（例如「t」）以最終字符串結尾： t.value1 + t.value2 + t.value3

它編譯好我檢查了它的錯別字和錯誤的名字（儘管可能我仍然錯過了一些東西）。當我嘗試在工作表中使用它時，我收到了「VALUE！」錯誤。下面的代碼保存在Excel中的VBA編輯器中的模塊中。

在此先感謝您的任何建議。

（附註：原諒我「VBA傻瓜」式的意見 - 這是因爲我上午一個VBA假！）

'Here we'll create the formula's structure - these are the bits the worksheet user will choose: 
    Function ConcatenateToAdd(ConcatenateRange as Range, Optional TableReference as String = "") As Variant 'the default value for TableReference will be "" 

    'And here are our other building blocks that we'll use behind the scenes: 

     Dim i As Long 

     Dim strResult1 As String 'this will be everything up to the last value 
     Dim strResult2 As String 'this will add the last value on to the string produced as strResult1 

     Dim Separator1 As String 
     Dim Separator2 As String 

     Separator1 = "."   'this will slip between the table reference and the field name 
     Separator2 = " + "   'this will go after each field name, except the last. 



    'Just in case - let's make a back-up plan 
     On Error GoTo ErrHandler 

    'OK - let's go! 

    'First, let's string together every value but the last one: 
     For i = 1 To ConcatenateRange.Count - 1           
        strResult1 = strResult1 & TableReference & Separator1 & ConcatenateRange.Cells(i).Value & Separator2 

     Next i 


    'Lovely! Now let's just add on the last one - this one won't have a + on the end. 

     For i = ConcatenateRange.Count - 0 To ConcatenateRange.Count + 0      'I'm sure this is not the most elegant way to phrase this... 

      strResult2 = strResult1 & TableReference & Separator1 & ConcatenateRange.Cells(i).Value 

     Next I 

'The next bit tells Excel what the final result of the formula should be, in the worksheet: 
ConcatenateToAdd = strResult2 


    'And this is what the error handler does - it will just make Excel shout "ERROR!" at you. Let's hope it doesn't need to. 
      ErrHandler: 
     ConcatenateToAdd = CVErr(xlErrValue) 

    'And that's all!  
     End Function 

Answer 1

你只是缺少的錯誤處理一點點。在您的代碼無論發生的結果將被設置爲一個錯誤值，因爲您：

一）設置ConcatenateToAdd = strResult2後不退出功能，或

b）檢查實際發生的錯誤在ErrHandler

試試像下面 - 我已經重構你的代碼一些，因爲你不需要兩個迴路（因此只需要strResult1）：

Option Explicit 

Function ConcatenateToAdd(ConcatenateRange As Range, Optional TableReference As String = "") As Variant 

    On Error GoTo ErrHandler 

    Dim i As Long 
    Dim strResult1 As String 
    Dim Separator1 As String 
    Dim Separator2 As String 

    ' update format if TableReference = "" 
    If TableReference = "" Then 
     Separator1 = "" 
    Else 
     Separator1 = "." 
    End If 
    Separator2 = " + " 

    strResult1 = "" 
    For i = 1 To ConcatenateRange.Count 
     strResult1 = strResult1 & TableReference & Separator1 & ConcatenateRange.Cells(i).Value 
     If i < ConcatenateRange.Count Then 
      strResult1 = strResult1 & Separator2 
     End If 
    Next i 

    ConcatenateToAdd = strResult1 

    'you could do an Exit Function here 
    'Exit Function 

' or continue into the ErrHandler block 
ErrHandler: 
    ' check an error actually occurred 
    If Err.Number <> 0 Then 
     ConcatenateToAdd = CVErr(xlErrValue) 
    End If 

    ' ConcatenateToAdd still equals strResult1 if no error occurred 

End Function 

要注意的一點是，該函數的返回正在建設的字符串後置：

ConcatenateToAdd = strResult1 

你可以做一個Exit Function作爲下一行，但如果你讓執行溜入ErrHandler塊，那麼你應該如果出現錯誤，則僅更新ConcatenateToAdd的值。你可以通過以下方式處理：

If Err.Number <> 0 Then 
    ConcatenateToAdd = CVErr(xlErrValue) 
End If