如何在VBA中处理可选的XML属性？

我已经写了一些代码来从XML文件导入一些数据到Excel中，直到它试图读取不存在的属性。 他们在文件中是可选的，我不能添加它们，所以我需要在代码中处理它。

我试着用If Is Not Nothing处理对象，但这不起作用， If <> ""或者If <> Null没有运气。

如果有人能给我任何帮助，我将非常感激。

 Public Sub import() Dim oDoc As MSXML2.DOMDocument Dim fSuccess As Boolean Dim oRoot As MSXML2.IXMLDOMNode Dim oSoftkey As MSXML2.IXMLDOMNode Dim oAttributes As MSXML2.IXMLDOMNamedNodeMap Dim oSoftkeyName As MSXML2.IXMLDOMNode Dim oSoftkeyDescriptor As MSXML2.IXMLDOMNode Dim oSoftkeyStyleName As MSXML2.IXMLDOMNode Dim oChildren As MSXML2.IXMLDOMNodeList Dim oChild As MSXML2.IXMLDOMNode Dim intI As Integer On Error GoTo HandleErr Set oDoc = New MSXML2.DOMDocument oDoc.async = False oDoc.validateOnParse = False fSuccess = oDoc.Load(ActiveWorkbook.Path & "\keys.xml") If Not fSuccess Then GoTo ExitHere End If intI = 2 ActiveSheet.Cells(1, 1).CurrentRegion.ClearContents ActiveSheet.Cells(1, 1) = "Name" ActiveSheet.Cells(1, 2) = "TextDescriptor" ActiveSheet.Cells(1, 3) = "StyleName" ' Get the root of the XML tree. ' Set oRoot = oDoc.DocumentElement Set oRoot = oDoc.SelectSingleNode("//IMS_Softkeys") ' Each IMS_Softkey in IMS_Softkeys For Each oSoftkey In oRoot.ChildNodes Set oAttributes = oSoftkey.Attributes Set oSoftkeyName = oAttributes.getNamedItem("Name") Set oSoftkeyDescriptor = oAttributes.getNamedItem("TextDescriptor") Set oSoftkeyStyleName = oAttributes.getNamedItem("StyleName") ActiveSheet.Cells(intI, 1).Value = oSoftkeyName.Text 'Can't handle optional attribute "TextDescriptor" or "SoftkeyStyle" ActiveSheet.Cells(intI, 2).Value = oSoftkeyDescriptor.Text ActiveSheet.Cells(intI, 3).Value = oSoftkeyStyleName.Text intI = intI + 1 Next oSoftkey ExitHere: Exit Sub HandleErr: MsgBox "Error " & Err.Number & ": " & Err.Description Resume ExitHere Resume End Sub 

示例XML文件（keys.xml）：

 <BATCH> <IMS_BATCH> <IMS_Softkeys> <IMS_Softkey Name="Donut" StyleName="Mer-Green-Yellow" TextDescriptor="1 Donut" /> <IMS_Softkey Name="Hotdog" StyleName="Mer-White-Black" TextDescriptor="11&quot; Hotdog" /> <IMS_Softkey Name="Coke_Image" TextDescriptor="Coke" /> <IMS_Softkey Name="DietCoke_Image" StyleName="Style for DietCocaCola" /> </IMS_Softkeys> </IMS_BATCH> </BATCH> 

Answer 1

它们是对象，在VBA中，使用以下语法检查它们是否为空 （ 已分配 ）

If Not (Object Is Nothing) Then

所以，如果你想检查属性是否从XML中检索和分配，那么你可以：

 ' Print only if the `oSoftKeyDescriptor` is not nothing If Not (oSoftkeyDescriptor Is Nothing) Then ActiveSheet.Cells(intI, 2).Value = oSoftkeyDescriptor.Text End If If Not (oSoftkeyStyleName Is Nothing) Then ActiveSheet.Cells(intI, 3).Value = oSoftkeyStyleName.Text End If 

我相信这是你所追求的结果