VB.Net, Linq to Xml: Is this the correct way to use logic while creating xml?

问题

While building an xml document I require to use logic to dictate the outcome of the xml; logically it is similar to the following piece of code (although this does not work):

    Dim buildElement As Boolean = True
    Dim xe As XElement = _
    <xml>
        <% If buildElement Then %>
        <BuildMyElement><%= buildElement.ToString %></BuildMyElement>
        <% End If %>
    </xml>

I have managed to do this using the method show below, is this the suggested way of doing this or is there a better one??

    Dim buildElement As Boolean = True
    Dim xe As XElement = _
    <xml>
        <%= If(buildElement, _
            <BuildMyElement><%= buildElement.ToString %></BuildMyElement>, _
            Nothing) %>
    </xml>

回答1:

when you use the If clause in one line you have 2 overload that are:

 IF(condition, true, false) 

or

 If(Condition,False)

You could write something like this to avoid assigning nothing value:

If(buildElement is nothing,<BuildMyElement><%= buildElement.ToString %></BuildMyElement>)

来源：https://stackoverflow.com/questions/5141565/vb-net-linq-to-xml-is-this-the-correct-way-to-use-logic-while-creating-xml