如何将 XML 子节点添加到多个父节点

Question

I have an xml file like this.

<ArrayOfALternateUnitModel>
<ALternateUnitModel>
<UnitId>1048</UnitId>
<Name> CARTON</Name>
</ALternateUnitModel>

<ALternateUnitModel>
<UnitId>2063</UnitId>
<Name> PACKET</Name>
</ALternateUnitModel>
</ArrayOfALternateUnitModel>

what i need is.

<ArrayOfALternateUnitModel>
<ALternateUnitModel>
<UnitId>1048</UnitId>
<Name> CARTON</Name>
<NewChild>new child</NewChild>
</ALternateUnitModel>

<ALternateUnitModel>
<UnitId>2063</UnitId>
<Name> PACKET</Name>
<NewChild>new child</NewChild>
</ALternateUnitModel>
</ArrayOfALternateUnitModel>

My code looks like this.

xmlDoc.Load(xmlStream);
XmlElement childElement = xmlDoc.CreateElement("NewChild");
childElement.InnerText = "new child";
XmlNode parentNode = xmlDoc.SelectSingleNode("ArrayOfALternateUnitModel/ALternateUnitModel");
parentNode.AppendChild(childElement);

Output goes like this.

<ArrayOfALternateUnitModel>
<ALternateUnitModel>
<UnitId>1048</UnitId>
<Name> CARTON</Name>
<NewChild>new child</NewChild>
</ALternateUnitModel>

<ALternateUnitModel>
<UnitId>2063</UnitId>
<Name> PACKET</Name>
</ALternateUnitModel>
</ArrayOfALternateUnitModel>

In the second node its not adding child nodes. How to add child to all parent nodes?

Answer 1

You take only one first node, so you can try to change these lines:

XmlNode parentNode = xmlDoc.SelectSingleNode("ArrayOfALternateUnitModel/ALternateUnitModel");
parentNode.AppendChild(childElement);

On

XmlNodeList parentNodes = xmlDoc.SelectNodes("ArrayOfALternateUnitModel/ALternateUnitModel");
foreach (XmlNode parentNode in parentNodes)
    parentNode.AppendChild(childElement);

Answer 2

Two problems:

• You cannot append a single element to multiple parents. An element can only have one parent.
• You need to select all the target elements, not just one.

This should work:

xmlDoc.Load(xmlStream);
foreach (XmlNode parent in xmlDoc.SelectNodes("ArrayOfALternateUnitModel/ALternateUnitModel"))
{
    XmlElement childElement = xmlDoc.CreateElement("NewChild");
    childElement.InnerText = "new child";

    parent.AppendChild(childElement);
}