<?xml version="1.0" encoding="utf-8" ?>
<bookstore>
    <book genre='Silverlight' publicationdate='12-22-2008' ISBN='978-0470193938'>
        <title>Professional Silverlight 2</title>
        <author>
            <first-name>Mike</first-name>
            <last-name>Meyers</last-name>
        </author>
        <price>49.99</price>
    </book>
    <book genre='Silverlight' publicationdate='02-15-2009' ISBN='978-1933988573'>
        <title>Hacking Silverlight 2</title>
        <author>
            <first-name>David</first-name>
            <last-name>Kelley</last-name>
        </author>
        <price>44.99</price>
    </book>
    <book genre='ASP.NET' publicationdate='10-20-2008' ISBN='978-0735626218'>
        <title>Microsoft ASP.NET and AJAX: Architecting Web Applications</title>
        <author>
            <first-name>Dino</first-name>
            <last-name>Esposito</last-name>
        </author>
        <price>39.99</price>
    </book>
</bookstore>

  <Canvas x:Name="LayoutRoot" Background="White">
        <TextBlock Text="输入图书类型：" Width="180" Canvas.Left="10" Canvas.Top="10" FontSize="14" />
        <TextBox x:Name="TextBoxGenre" Width="180" Height="30" FontSize="14"
            Canvas.Left="10" Canvas.Top="50" />
        <Button x:Name="ButtonGenre" Content="确定" Width="120" Height="40"
            Canvas.Left="40" Canvas.Top="100"  Click="ButtonGenre_Click" />
        <TextBlock Text="输入作者姓名：" Width="180" Canvas.Left="210" Canvas.Top="10" FontSize="14" />
        <TextBox x:Name="TextBoxAuthor" Width="180" Height="30" FontSize="14"
            Canvas.Left="210" Canvas.Top="50" />
        <Button x:Name="ButtonAuthor" Content="确定" Width="120" Height="40"
            Canvas.Left="240" Canvas.Top="100"  Click="ButtonAuthor_Click"/>
        <TextBlock x:Name="TextBlockResult" Text="查询结果：" FontSize="14"
            Canvas.Left="10" Canvas.Top="150" TextWrapping="Wrap" />
    </Canvas>

XmlReader reader;
        string author;
        public xmlquery()
        {
            InitializeComponent();
            DownloadFile();
        }
        private void ButtonGenre_Click(object sender, RoutedEventArgs e)
        {
            string genre = TextBoxGenre.Text;           
            while (reader.Read())
            {
                if (reader.ReadToFollowing("book"))
                {
                    reader.MoveToAttribute("genre");
                    reader.GetAttribute("genre");
                    string strgenre = reader.Value;
                    if (strgenre == genre)
                    {
                        if (reader.ReadToFollowing("title"))
                        {
                            string title=    reader.ReadElementContentAsString();
                            TextBlockResult.Text += "\n书名：" + title;
                        }                        
                    }
                }
            }
            reader.Close();
        }
        private void RequestProceed(IAsyncResult asyncResult)
        {
            HttpWebRequest request = asyncResult.AsyncState as HttpWebRequest;
            Stream requestStream = request.EndGetRequestStream(asyncResult);
            using (StreamWriter writer = new StreamWriter(requestStream))
            {
                writer.Write("author=" + author);
                writer.Flush();
            }
            request.BeginGetResponse(new AsyncCallback(ResponseProceed), request);
        }
        void ResponseProceed(IAsyncResult asyncResult)
        {
            HttpWebRequest request = asyncResult.AsyncState as HttpWebRequest;
            HttpWebResponse response = request.EndGetResponse(asyncResult) as HttpWebResponse;
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
            Action<StreamReader> showInfo = this.ShowBookInfo;
            this.Dispatcher.BeginInvoke(showInfo, reader);
        }
        void ShowBookInfo(StreamReader reader)
        {
            TextBlockResult.Text = "查询结果：\n" + reader.ReadToEnd();
        }private void ButtonAuthor_Click(object sender, RoutedEventArgs e)
        {
            author = TextBoxAuthor.Text;
            Uri address = new Uri("http://localhost:4995/BookStoreHandler.ashx");
            HttpWebRequest request = WebRequest.Create(address) as HttpWebRequest;
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.BeginGetRequestStream(new AsyncCallback(RequestProceed), request);

        }

public void ProcessRequest(HttpContext context)
        {//string genre = context.Request.Form["genre"].ToString();
            //string result = GetBookInfo(genre);

            string author = context.Request.Form["author"].ToString();
            string result = GetBookInfobyname(author);
            context.Response.Write(result);
            
        }
 private string GetBookInfobyname(string name)
        {
            StringBuilder builder = new StringBuilder();

            XmlDocument document