c#xml追加读取节点

读取
if (File.Exists("Book.xml"))
{
XmlDocument doc = new XmlDocument();
doc.Load("Book.xml");
XmlElement root = doc.DocumentElement;
XmlNodeList nodelist = root.ChildNodes;
foreach (XmlNode item in nodelist)
{
Console.WriteLine(item.InnerText);
}
Console.ReadKey();

}

if (File.Exists("Book.xml"))
{
XmlDocument doc = new XmlDocument();
doc.Load("Book.xml");
XmlNodeList nodelist = doc.SelectNodes("/order/Items/OrderItem");
foreach (XmlNode item in nodelist)
{
Console.WriteLine(item.Attributes["Name"].Value);
Console.WriteLine(item.Attributes["Count"].Value);
}
Console.ReadKey();
}

追加
static void Main(string[] args)
{
//XmlDocument xm = new XmlDocument();
//XmlDeclaration doc = xm.CreateXmlDeclaration("1.0", "utf-8", "yes");
//xm.AppendChild(doc);
//XmlElement t1 = xm.CreateElement("order");
//xm.AppendChild(t1);
//XmlElement t2 = xm.CreateElement("CustomerName");
//t1.AppendChild(t2);
//t2.InnerXml = "<p>我是一个P标签</p>";
//XmlElement t3 = xm.CreateElement("CustomerNumber");
//t1.AppendChild(t3);
//t3.InnerText = "<p>我是一个P标签</p>";
//XmlElement t4 = xm.CreateElement("Items");
//t1.AppendChild(t4);
//XmlElement i1 = xm.CreateElement("OrderItem");
//t4.AppendChild(i1);
//i1.SetAttribute("Name","码表");
//i1.SetAttribute("Count", "10");
//XmlElement i2 = xm.CreateElement("OrderItem");
//t4.AppendChild(i2);
//i2.SetAttribute("Name", "雨衣");
//i2.SetAttribute("Count", "5");
//XmlElement i3 = xm.CreateElement("OrderItem");
//t4.AppendChild(i3);
//i3.SetAttribute("Name", "手套");
//i3.SetAttribute("Count", "10");
//xm.Save("a.xml");

//有追加 没有 创建

XmlDocument xm = new XmlDocument();
XmlElement t1;
XmlElement t2;
XmlElement t3;

if (File.Exists("1.xml"))
{

//加载xml文档到doc
xm.Load("1.xml");

//获取根节点
t1 = xm.DocumentElement;

}
else
{
XmlDeclaration doc = xm.CreateXmlDeclaration("1.0", "utf-8", "yes");
xm.AppendChild(doc);
t1 = xm.CreateElement("order");
xm.AppendChild(t1);

}

xm.Save("1.xml");

}

if (File.Exists("Book.xml"))
{
doc.Load("Book.xml");
//XmlNodeList nodelist = doc.SelectNodes("/order/Items");
XmlNode nodelist = doc.SelectSingleNode("/order/Items");
XmlElement orderitems = doc.CreateElement("orderitems");
orderitems.SetAttribute("Name", "雨衣");
orderitems.SetAttribute("Count", "10");
nodelist.AppendChild(orderitems);
//foreach (XmlNode item in nodelist)
//{
//    item.AppendChild(orderitems);

//}
Console.ReadKey();
doc.Save("Book.xml");

}

删除XML
if (File.Exists("Book.xml"))
{
XmlDocument doc = new XmlDocument();
doc.Load("Book.xml");
XmlNode nodelist = doc.SelectSingleNode("/order/Items");
nodelist.RemoveAll();
doc.Save("Book.xml");
Console.ReadKey();
}