初识.net界面程序（9）--LINQ To XML

<CScore>
<StuID>
<name>张三</name>
<score>86</score>
</StuID>
<StuID>
<name>李四</name>
<score>87</score>
</StuID>
<StuID>
<name>王五</name>
<score>87</score>
</StuID>
<StuID>
<name>刘七</name>
<score>88</score>
</StuID>
<StuID>
<name>张八</name>
<score>87</score>
</StuID>
</CScore>

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml.Linq;

namespace 补充习题
{
public partial class Form1 : Form
{

public Form1()
{
InitializeComponent();
textBox1.Anchor =
AnchorStyles.Left | AnchorStyles.Right
| AnchorStyles.Top | AnchorStyles.Bottom;
textBox1.ScrollBars = ScrollBars.Both;
foreach (var v in this.Controls)
{
Button btn = v as Button;
if (btn != null)
{
btn.Anchor = AnchorStyles.Bottom | AnchorStyles.Left;
btn.Click += btn_Click;
}
}
}

void btn_Click(object sender, EventArgs e)
{
string vlaue = textBox2.Text;
string s = (sender as Button).Text;
switch (s)
{
case "创建":
{

XElement xTree = new XElement("CScore",

new XElement("StuID",
new XElement("name", "张三"),
new XElement("score", 86)
),
new XElement("StuID",
new XElement("name", "李四"),
new XElement("score", 87)
),
new XElement("StuID",
new XElement("name", "王五"),
new XElement("score", 87)
),
new XElement("StuID",
new XElement("name", "刘七"),
new XElement("score", 88)
),
new XElement("StuID",
new XElement("name", "张八"),
new XElement("score", 87)
)
);

textBox1.Text = xTree.ToString();
xTree.Save("test.xml");
break;
}
case "查询":
{
StringBuilder sb = new StringBuilder();
XElement CScore = null;
try
{
CScore = XElement.Load("test.xml");
}
catch
{
MessageBox.Show("请先执行【创建】");
return;
}
var q1 = from t in CScore.Elements("StuID")
select t;

var q2 = from t in q1
where (string)t.Element("score") == vlaue
select t.Element("name");
foreach (var v in q2)
{
sb.AppendLine(v.Value.ToString());
}
//sb.AppendLine();
textBox1.Text = sb.ToString();
break;
}
}
}
}
}