[求助]如何使用C#语言在xml文档中批量插入节点

我这里有个xml的
<?xml version="1.0" encoding="utf-8" ?>
<Group>
<Person>
<Name>John Smith</Name>
<Age>21</Age>
<Gender>male</Gender>
<Address>Road 1</Address>
</Person>
<Group>
<Person>
<Name>John see</Name>
<Age>23</Age>
<Gender>male</Gender>
<Address>Road 2</Address>
</Person>
</Group>
这个是我的xml文件
我用这个方法读取元素name age gender address
public void ReadXml()
{
   XmlTextReader reader = new XmlTextReader(@"C:\XMLFile1.xml");
   while(reader.Read())
   {
     if(reader.NodeType == XmlNodeType.Element && reader.Name =="Person")
     {
 while(!(reader.NodeType == XmlNodeType.EndElement && reader.Name == "Person"))
 {
   string name;
   int age;
   string gender;
   string address;
   if(reader.NodeType == XmlNodeType.Element)
   {
  switch(reader.Name)
  {
   case"Name":
   name = reader.ReadString();
   break;
   case"Age":
   age = Int32.Parse(reader.ReadString());
    break;
   case"Gender":
   gender = reader.ReadString();
   break;
   case"Address":
   address = reader.ReadString();
   break;
   default:
   break；
   }
  }
  MessageBox.Show(name+""+Convert.ToInt32(age)+""+gender+""+address);
     }
     }
    }
}