Microsoft Visual Studio 2010 Express for Window Phone

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Microsoft Visual Studio 2010 Express for Window Phone

Guardando i video del MIX mi è venuta voglia di provare a fare un piccolo programma in Window Phone per la lettura dei feed RSS. Così presi armi e bagagli mi sono documentato ed ecco qua in pochi click ho il mio lettore.

Ma è così difficile ? Non direi proprio anzi ( una goduria… ) Prima di tutto ho scaricato dal sito http://www.microsoft.com/express/phone/ la mia versione di Microsoft Visual Studio 2010 Express for Window Phone che contiene “solo” IExplorer ( la prima cosa che ho fatto è stata collegarmi a facebook ed inserire un post ). Poi al solito creo un nuovo progetto e mi si apre una fantastica schermata ( xaml a destra ed emulatore a sinistra ).

inizio ad inserire i miei Textbox, Button, Label come se fossi su un’applicazione Silverlight

Xaml

        1: <phoneNavigation:PhoneApplicationPage 

       2:     x:Class="WindowsPhoneApp.MainPage"

       3:     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

       4:     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

       5:     xmlns:phoneNavigation="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Navigation"

       6:     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

       7:     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

       8:     mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="800"

       9:     FontFamily="{StaticResource PhoneFontFamilyNormal}"

    FontSize="{StaticResource PhoneFontSizeNormal}"

    Foreground="{StaticResource PhoneForegroundBrush}">

  

    

    <Grid x:Name="LayoutRoot" HorizontalAlignment="Stretch"

          Background="{StaticResource PhoneBackgroundBrush}">

        <Grid.RowDefinitions>

            <RowDefinition Height="Auto"/>

            <RowDefinition Height="Auto"/>

            <RowDefinition Height="*"/>

        </Grid.RowDefinitions>

        

        <Grid x:Name="TitleGrid" Grid.Row="0">

            <TextBlock Text="MY APPLICATION" Grid.Row="0" x:Name="textBlockPageTitle" Style="{StaticResource PhoneTextPageTitle1Style}"/>

            <TextBlock Text="RSS Reader" Grid.Row="0" x:Name="textBlockListTitle" Style="{StaticResource PhoneTextPageTitle2Style}"/>

        </Grid>

         <StackPanel Grid.Row="1" Orientation="Horizontal">

            <TextBlock HorizontalAlignment="Left" Margin="10,30,10,10" Text="Url :" VerticalAlignment="Top" />

            <TextBox HorizontalAlignment="Left" Text="http://blogs.ugidotnet.org/sonny/Rss.aspx" Width="310"

                     Name="_tbUrl" VerticalAlignment="Top" HorizontalContentAlignment="Stretch"/>

            <Button Content="Read" HorizontalAlignment="Left" Name="_bRead" VerticalAlignment="Top" Click="_bRead_Click"  />

         </StackPanel>

        <ListBox Grid.Row="2" HorizontalAlignment="Left" HorizontalContentAlignment="Stretch"

                 Name="_lbRssItems" VerticalAlignment="Top">

            <ListBox.ItemTemplate>

                <DataTemplate>

                    <StackPanel Orientation="Horizontal" Height="132">

                        <StackPanel Width="390">

                            <TextBlock Text="{Binding Title}" Foreground="#FFC8AB14" FontSize="28" />

                            <TextBlock Text="{Binding Description}" Height="100" TextWrapping="Wrap" FontSize="24" />

                            <HyperlinkButton NavigateUri="{Binding Link}" Content="Apri Feed" />

                        </StackPanel>

                    </StackPanel>

                </DataTemplate>

            </ListBox.ItemTemplate>

  

        </ListBox>

    </Grid>

    

</phoneNavigation:PhoneApplicationPage>

Metto in ordine i miei Binding, creo la mia entità RSSItem

       1: public class RSSItem

       2:     {

       3:         public string Title { get; set; }

       4:         public string Link { get; set; }

       5:         public string Description { get; set; }

       6:     }

Ed inizio a scrivere nella mia classe MainPage

       1: public partial class MainPage : PhoneApplicationPage

       2:     {

       3:         public MainPage()

       4:         {

       5:             InitializeComponent();

       6:  

       7:             SupportedOrientations = SupportedPageOrientation.Portrait | SupportedPageOrientation.Landscape;

       8:         }

       9:  

        private void _bRead_Click(object sender, RoutedEventArgs e)

        {

            GetRSSfile();

        }

  

        private void GetRSSfile()

        {

            if (_tbUrl.Text == string.Empty) return;

  

            System.Uri uri = new Uri(_tbUrl.Text);

            HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(uri);

            httpWebRequest.AllowReadStreamBuffering = false;

            IAsyncResult result = (IAsyncResult)httpWebRequest.BeginGetResponse(

                                        new AsyncCallback(RespCallback), httpWebRequest);

        }

  

        private void RespCallback(IAsyncResult asynchronousResult)

        {            

                HttpWebRequest myHttpWebRequest2 = (HttpWebRequest)asynchronousResult.AsyncState;

                HttpWebResponse response = (HttpWebResponse)myHttpWebRequest2.EndGetResponse(asynchronousResult);

  

                string text;

                using(StreamReader sr = new StreamReader(response.GetResponseStream()))

                          text = sr.ReadToEnd();

  

                LoadRSSItems(text);            

        }

  

        private void LoadRSSItems(string text)

        {

            if (text == string.Empty) return;

  

            XElement element = XElement.Parse(text);

  

            var ents = from node in element.Descendants("channel").Descendants("item")

                                        select new RSSItem

                                        {

                                            Title = node.Descendants("title").FirstOrDefault().Value,

                                            Link = node.Descendants("link").FirstOrDefault().Value,

                                            Description = HttpUtility.HtmlDecode(

                                                node.Descendants("description").FirstOrDefault().Value),

                                        };

  

            Dispatcher.BeginInvoke(() => { _lbRssItems.ItemsSource = ents; });            

        }

    }