如何修复if语句来检查3个元素？ [英] How do I fix my if statement to check 3 elements?

问题描述

我在下面的if语句没有工作，因为我希望它工作。 objXMLInputDoc中的xml文档有3个可选元素， AddPersonContactInformation ， PersonTelephoneNumber 和 PersonEmailAddress

我想做什么是检查3个元素中是否存在并继续。如果all都不存在，则if语句将退出并显示错误。

当所有元素都不存在时它正在工作。但是，当存在一个元素时，if语句仍然存在。如何修复if语句，以便在存在一个元素时，它不会以错误退出？



此示例xml文档分配给objXMLInputDoc。这就是if语句访问它及其元素的方式。

示例xml文档

 < ;   xml     version   =  1.0   编码  =  UTF-8 ？ >  
 <   soap：Envelope  >  
 <  < span class =code-leadattribute> soap：正文 >  
 <   AddPersonContactInformation  >  
 <   PersonAddress  >  
 <   AddressUSStandard  >  
 <   AddressAttention  >  Mr Smith <   / AddressAttention  >  
 <   / AddressUSStandard  >  
 <   / PersonAddress  >  
 <！ -    < P. ersonTelephoneNumber telephoneNumberUsageText =Home> 
<电话> 698-478-4612< /电话> 
< / PersonTelephoneNumber>    - >   
 < ;！ -    < PersonEmailAddress> [e-mail]< / PersonEmailAddress>    - >   
 <   / AddPersonContactInformation  >  
 <   / soap：Body  >  
 <   / soap：Envelope  >  

如果声明不起作用

 如果（（objXMLInputDoc.DocumentElement.SelectSingleNode（   AddPersonContactInforma / PersonAddress）  没什么）并且（objXMLInputDoc.DocumentElement.SelectSingleNode（  AddPersonContactInformation / PersonTelephoneNumber）   Nothing ）和（objXMLInputDoc.DocumentElement.SelectSingleNode（< span class =code-string>  AddPersonContactInformation / PersonEmailAddress）   Nothing ））然后 
 ' < span class =code-comment>退出 
 退出  Sub  
 结束 如果 

我是什么尝试过：

 如果（（objXMLInputDoc。 DocumentElement.SelectSingleNode（  AddPersonContactInformation / PersonAddress）   Nothing ）和（objXMLInputDoc.DocumentElement.SelectSingleNode（  AddPersonContactInformation / PersonTelephoneNumber）  没有）和（objXMLInputDoc.DocumentElement.SelectSingleNode（  AddPersonContactInformation / PersonEmailAddress）   Nothing ））然后 
 ' 退出 
 退出  Sub  
 结束 如果 

解决方案

SelectSingleNode 需要一个从当前节点开始的XPath表达式。



由于 AddPersonContactInformation 不是root元素的直接子元素，你的XPath表达式将不匹配任何内容。



将表达式更改为以<$开头c $ c> // 匹配文档中任何位置的元素：

 如果（（objXMLInputDoc.DocumentElement.SelectSingleNode（  // AddPersonContactInformation / PersonAddress）    Nothing ） AndAlso （objXMLInputDoc.DocumentEleme nt.SelectSingleNode（  // AddPersonContactInformation / PersonTelephoneNumber）是  Nothing ） AndAlso （objXMLInputDoc.DocumentElement.SelectSingleNode（  // AddPersonContactInformation / PersonEmailAddress）   Nothing ））然后 
 ' 退出 
 退出  Sub  
 结束 如果 

XPath教程 [ ^ ]

<小时ef =https://msdn.microsoft.com/en-us/library/ms256471(v=vs.110).aspx> XPath语法 [ ^ ]



（ NB：你的XML似乎无效 - 你错过了 soap 名称空间声明。）

I have the if statement below that is not working as I expect it to work. The xml document in objXMLInputDoc has 3 optional elements, AddPersonContactInformation, PersonTelephoneNumber and PersonEmailAddress
What I am trying to do is to check if any of the 3 elements exist and continue. If all are not present, the if statement will exit with an error.
It is working when all elements are not present. However when one element is present, the if statement still exists like. How do I fix the if statement so that, when there is one element present, it does not exit with an error?

This sample xml document is assigned to objXMLInputDoc. This is how if statement is accessing it and its elements.
Sample xml document

<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope>
	<soap:Body>
		<AddPersonContactInformation>
			<PersonAddress>
				<AddressUSStandard>
					<AddressAttention>Mr Smith</AddressAttention>
				</AddressUSStandard>
			</PersonAddress>
			<!--<PersonTelephoneNumber telephoneNumberUsageText="Home">
				<Telephone>698-478-4612</Telephone>
			</PersonTelephoneNumber>-->
			<!--<PersonEmailAddress>[e-mail]</PersonEmailAddress>-->
		</AddPersonContactInformation>
	</soap:Body>
</soap:Envelope>

If statement not working

If ((objXMLInputDoc.DocumentElement.SelectSingleNode("AddPersonContactInformation/PersonAddress") Is Nothing) And (objXMLInputDoc.DocumentElement.SelectSingleNode("AddPersonContactInformation/PersonTelephoneNumber") Is Nothing) And (objXMLInputDoc.DocumentElement.SelectSingleNode("AddPersonContactInformation/PersonEmailAddress") Is Nothing)) Then
'exit 
 Exit Sub
End If

What I have tried:

If ((objXMLInputDoc.DocumentElement.SelectSingleNode("AddPersonContactInformation/PersonAddress") Is Nothing) And (objXMLInputDoc.DocumentElement.SelectSingleNode("AddPersonContactInformation/PersonTelephoneNumber") Is Nothing) And (objXMLInputDoc.DocumentElement.SelectSingleNode("AddPersonContactInformation/PersonEmailAddress") Is Nothing)) Then
'exit 
 Exit Sub
End If

解决方案

SelectSingleNode expects an XPath expression which starts at the current node.

Since AddPersonContactInformation is not a direct child of the root element, your XPath expression won't match anything.

Change your expressions to start with "//" to match the element anywhere in the document:

If ((objXMLInputDoc.DocumentElement.SelectSingleNode("//AddPersonContactInformation/PersonAddress") Is Nothing) AndAlso (objXMLInputDoc.DocumentElement.SelectSingleNode("//AddPersonContactInformation/PersonTelephoneNumber") Is Nothing) AndAlso (objXMLInputDoc.DocumentElement.SelectSingleNode("//AddPersonContactInformation/PersonEmailAddress") Is Nothing)) Then
'exit 
 Exit Sub
End If

XPath Tutorial[^]
XPath Syntax[^]

(NB: Your XML seems to be invalid - you're missing the soap namespace declaration.)

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