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using System;
using System.IO;
using System.Xml.Serialization;

class Program {
    static void Main(string[] args) {
        string Path = System.IO.Path.GetDirectoryName(Environment.GetCommandLineArgs()[0]) + "\\ShowPrice.xml";
        XmlSerializer serializer = new XmlSerializer(typeof(Item));

        //値セット
        Item item = new Item { Name = "りんご", Cost = 200 };

        //書き込み
        using(StreamWriter sw = new StreamWriter(Path)) {
            serializer.Serialize(sw, item);
        }

        //ファイル内容表示
        using(StreamReader sr = new StreamReader(Path)) {
            Console.WriteLine(sr.ReadToEnd());
        }
        Console.ReadLine();

        //読み込み,表示
        using(StreamReader sr = new StreamReader(Path)) {
            item = (Item)(serializer.Deserialize(sr));
        }
        Console.WriteLine("「{0}」は{1}円(税込み)", item.Name, item.Cost * 1.05);
        Console.ReadLine();
    }
}

public class Item {
    public string Name { set; get; }
    public int Cost { set; get; }
}