使用正则表达式从字符串中删除属性值不是特定值的所有 xml 节点

Question

I would like to remove all xml nodes where name is not a number of values:

<Property Name="Operation" Type="String" Access="ReadWrite" Value="ProduceFile" />
<Property Name="BackOfficeType" Type="String" Access="ReadWrite" Value="growBusiness Solutions" />
<Property Name="module" Type="String" Access="ReadWrite" Value="Document" />
<Property Name="vti_pluggableparserversion" Type="String" Access="ReadOnly" Value="16.0.0.20405" />
<Property Name="_Author" Type="String" Access="ReadWrite" Value="hfhf fghfgh" />
<Property Name="modifiedBy" Type="String" Access="ReadWrite" Value="fghfghfghfg" />
<Property Name="vti_parserversion" Type="String" Access="ReadOnly" Value="16.0.0.20405" />

How do I remove all element above with regex where Name is not Operation or module?

I was thinking something like:

xml = Regex.Replace(xml, @"<Property Name=""(?!Operation |module)"".*?/>", "");

But this is not working.

Answer 1

I don't understand why, because " is not a special character in the C# Regex system, but removing the second quote and the space after Operation makes it work (this is without the necessary escaping):

<Property Name="(?!Operation|module).*?/>

I'll update this answer if I figure out what's going on with that second quote.

EDIT: Well I feel a fool for not noticing this myself. A friend of mine pointed out that by having Name="(?!Operation|module)" it essentially says "Only match on Name="" . If you add the following example to your sample data you'll see that's what is happening:

<Property Name="" Type="String" Access="ReadOnly" Value="16.0.0.20405" />

So adding another wildcard inside the quotes will allow it to match on all the entries that don't have "Operation" or "module" in them:

<Property Name="(?!Operation|module).*".*?/>

However, this raises a new issue, which is now if you have Name="Operation Awesome" the filtering group will ignore it as well. So the negative lookahead would have to be changed somehow to specifically ignore exact words and not property names simply containing the words. So how do we do that?

<Property Name=(?!"Operation"|"module").*?/>

This ensures it only keep an exact match of "Operation" or "module" . The only side effect present now is it will delete any malformed XML like PropertyName="Operation Type="string" . You may consider this a negative, but if you want to be able to handle invalid XML you should be doing so with another method before this one.