C#：如何在文本框中获取xml值？

我有一个XML文件

<current>
<city>
<country>JAPAN</country>
</city>
<temperature value="307.07" min="307.07" max="307.07" unit="kelvin"/>
</current>

使用xml linq：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.IO;

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            string xml = File.ReadAllText(FILENAME);

            XDocument doc = XDocument.Parse(xml);

            decimal temperature = (decimal)doc.Descendants("temperature").First().Attribute("value");
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.IO;

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            string xml = File.ReadAllText(FILENAME);

            XDocument doc = XDocument.Parse(xml);

            decimal temperature = (decimal)doc.Descendants("temperature").First().Attribute("value");
        }
    }
}