Question

how i can add new tag in xml file by use linq to xml and i want the new tag the first tag

<?xml version="1.0" encoding="utf-8"?>
<settings>
<Device>
  <username>fooo</username>
  <AgentName>fooo</AgentName>
  <password>fooo</password>
</Device>
<Device>
  <username>fooo1</username>
  <AgentName>fooo1</AgentName>
  <password>fooo1</password>
</Device>
</settings>

now i want to add a new tag to make file like that

<settings>
<IncommingConfig>
    <ip>10.100.101.18</ip>
    <port>5060</port>
</IncommingConfig>
<Device>
  <username>fooo</username>
  <AgentName>fooo</AgentName>
  <password>fooo</password>
</Device>
<Device>
  <username>fooo1</username>
  <AgentName>fooo1</AgentName>
  <password>fooo1</password>
</Device>
</settings>

Answer 1

That’s easy using XContainer.AddFirst, which adds the given value as the first child:

XDocument doc = XDocument.Load("data.xml");
doc.Root.AddFirst(new XElement("IncomingConfig", // Fixed typo in name
                     new XElement("ip", ipAddress),
                     new XElement("port", port)));
doc.Save("output.xml");