检查XElement是否存在多个可能的XElement之一 [英] Checking an XElement for Existence of One of Several Possible XElements

问题描述

是否可以确定XElement是否包含任何指定的元素之一?例如，我有要检查的XElement:

Is there a way to determine if an XElement contains one of any specified elements? For example, I have XElements that I'll want to check:

Dim xe1 = <color><blue/></color>
Dim xe2 = <color><red/></color>
Dim xe3 = <color><powderBlue/></color>
Dim xe4 = <color><aqua/></color>
Dim xe5 = <color><green/></color>

我希望能够查询任何Xelements，以查看它们是否包含它们下面的元素<red/>，<green/>或<blue/>，如果是，则返回true，否则返回false.

I'd like to be able to query any of the xelements to see if they containt the elements <red/>, <green/> or <blue/> below them and return true if so, false if not.

我希望这会更简单，但是我能想到的最好的方法是:

I was hoping that it would be simplier, but the best I could come up with was:

Dim primaryColor = From e In xe1.Elements Where e.Name = "blue" Or e.Name = "red" Or e.Name = "green"
Dim primaryColorTrue = primaryColor.SingleorDefault
If primaryColorTrue IsNot Nothing Then
'Blah
End If

有人能更好地做到这一点吗，例如将红色/绿色/蓝色的xelements放入数组中并使用Elements.Contains(元素列表)之类的东西?

Does anyone have a better way to do this, such as putting those xelements of red/green/blue into an array and using something like Elements.Contains(list of elements)?

推荐答案

如果我正确理解-也许(使用C#，对不起-但此处没有真正的C#特定逻辑):

If I understand correctly - perhaps (using C#, sorry - but no real C# specific logic here):

var colors = new[] {"red", "green","blue"};
bool any = el.Descendants().Any(child => colors.Contains(child.Name.LocalName));

即使VB与您抗争，我敢肯定您可以使用.Any代替.SingleOrDefault和null支票.

Even if the VB fights you, I'm sure you can use .Any instead of .SingleOrDefault and a null check.

有关信息，在这里使用元素听起来很奇怪；如果可能的话，我只是将颜色名称作为 text :

For info, using elements here to me sounds like an odd idea; I'd just have the color name as the text if possible:

<somexml><color>blue</color></somexml>

或什至作为属性:

<somexml color="blue"/>

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