Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

            LasteventSettingSection last = new LasteventSettingSection();

            config.Sections.Add("lastevent", last);
             config.Save();

 1  System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
 2             doc.Load("ConfigurationTest.exe.Config");
 3 
 4             XmlNodeList nodes = doc.ChildNodes[1].ChildNodes;
 5 
 6             foreach (XmlNode node in nodes)
 7             {
 8                 Console.WriteLine(node.InnerXml);
 9             }
10 
11 
12             XmlNode newnode = doc.ChildNodes[1];
13 
14             foreach (XmlNode v in newnode.ChildNodes)
15             {
16                 if (v.Name == "lastevent")
17                 {
18                     Console.WriteLine("lastevent 已经存在");
19                     return;
20                 }
21             }
22 
23             XmlElement elem = doc.CreateElement("lastevent");
24             XmlAttribute att = doc.CreateAttribute("name");
25             att.Value = http://www.mamicode.com/"用于替换lastevent中不想看到的内容";
26             elem.Attributes.Append(att);
27 
28 
29             XmlElement Items = doc.CreateElement("Items");
30             elem.AppendChild(Items);
31 
32 
33             XmlElement add1 = doc.CreateElement("add");
34 
35             XmlAttribute original = doc.CreateAttribute("original");
36             original.Value = http://www.mamicode.com/"original";
37             add1.Attributes.Append(original);
38 
39             XmlAttribute replacement = doc.CreateAttribute("replacement");
40             replacement.Value = http://www.mamicode.com/"replacement";
41             add1.Attributes.Append(replacement);
42 
43             Items.AppendChild(add1);
44 
45             elem.AppendChild(Items);
46 
47 
48             newnode.AppendChild(elem);
49 
50             doc.Save("111.config");