What is Json : - Json means Java Script Object Notation web service which returns the data in lightweight format . JSON is a way of representing objects (as also noted in its name).

Difference between xml and json :-

XML Web services poses some serious problems - the heavy payload and the associated cost in transporting them over the network and parsing them on the client side make them clunky to work with. A much better approach is to develop JSON (Java Script Object Notation) Web services, which returns the result in a lightweight format JSON provides better language-independent representation of data structures. JSON handles mixed content adequately That's not to say XML's handling of mixed content is inadequate, only that JSON's minimal mixed content support isn't a deal breaker.

Consuming Json in Wp7 Application and parse data : -

Step1 :- Create a New Project with name of jsonservice.

Step 2: - To consume this JSON Web service in your Windows Phone 7 application, you need to add a reference to the System.Servicemodel.Web.dll ,System.Servicemodel. and System.Runtime.Serialization in your project

Step 3 .Add new Class Name AddressList in your project and  just copy Paste following code in this class

using System;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Ink;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using System.Runtime.Serialization;

namespace JasonService

{

    public class AddressList

    {

        public string placeName { get; set; }

        public double latitude{ get; set; }

        public double lngtitude{ get; set; }

    }

    [DataContract]

    public class Postal_Result

    {

       [DataMember(Name = "postalcodes")]

        public AddressList[] addresses;

    }

}

Step 4.

Now  Open Your MainPage.xaml file and Copy Paste Following Code

<phone:PhoneApplicationPage

    x:Class="JasonService.MainPage"

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

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

    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"

    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"

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

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

    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"

    FontFamily="{StaticResource PhoneFontFamilyNormal}"

    FontSize="{StaticResource PhoneFontSizeNormal}"

    Foreground="{StaticResource PhoneForegroundBrush}"

    SupportedOrientations="Portrait" Orientation="Portrait"

    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->

    <Grid x:Name="LayoutRoot" Background="Transparent">

        <Grid.RowDefinitions>

            <RowDefinition Height="Auto"/>

            <RowDefinition Height="*"/>

        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->

        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">

            <TextBlock x:Name="ApplicationTitle" Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>

            <TextBlock x:Name="PageTitle" Text="page name" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>

        </StackPanel>

        <!--ContentPanel - place additional content here-->

        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">

            <Button Content="Click" Height="72" HorizontalAlignment="Left" Margin="278,20,0,0" Name="button1" VerticalAlignment="Top" Width="160" Click="button1_Click" />

            <ComboBox Width="250" Height="50" Name="PlaceName_combobox" Visibility="Visible" FontSize="24" FontWeight="Bold" Foreground="Black" SelectionChanged="font_combobox_SelectionChanged" Margin="151,119,55,438">

            </ComboBox>

            <ComboBox Width="250" Height="50" Name="lat_combobox" Visibility="Visible" FontSize="24" FontWeight="Bold" Foreground="Black" SelectionChanged="font_combobox_SelectionChanged" Margin="151,279,55,278">

            </ComboBox>

            <ComboBox Width="250" Height="50" Name="lan_combobox" Visibility="Visible" FontSize="24" FontWeight="Bold" Foreground="Black" SelectionChanged="font_combobox_SelectionChanged" Margin="151,195,55,362">

            </ComboBox>

            <TextBlock Height="50" HorizontalAlignment="Left" Margin="12,119,0,0" Name="textBlock1" Text="Place" VerticalAlignment="Top" Width="133" />

            <TextBlock Height="50" HorizontalAlignment="Left" Margin="12,195,0,0" Name="textBlock2" Text="Langtitude" VerticalAlignment="Top" Width="133" />

            <TextBlock Height="50" HorizontalAlignment="Left" Margin="9,279,0,0" Name="textBlock3" Text="Longtitude" VerticalAlignment="Top" Width="133" />

            <TextBlock Height="54" HorizontalAlignment="Left" Margin="12,20,0,0" Name="textBlock4" Text="Click Button To call Service" VerticalAlignment="Top" Width="260" />

        </Grid>

    </Grid>

    <!--Sample code showing usage of ApplicationBar-->

    <!--<phone:PhoneApplicationPage.ApplicationBar>

        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">

            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>

            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>

            <shell:ApplicationBar.MenuItems>

                <shell:ApplicationBarMenuItem Text="MenuItem 1"/>

                <shell:ApplicationBarMenuItem Text="MenuItem 2"/>

            </shell:ApplicationBar.MenuItems>

        </shell:ApplicationBar>

    </phone:PhoneApplicationPage.ApplicationBar>-->

</phone:PhoneApplicationPage>

Step 5 .At last open your MainPage.xaml.cs page and copy paste following code

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using Microsoft.Phone.Controls;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Json;

namespace JasonService

{

    public partial class MainPage : PhoneApplicationPage

    {

        // Constructor

        public MainPage()

        {

            InitializeComponent();

            PlaceName_combobox.Items.Add("Place");

            PlaceName_combobox.SelectedIndex = 0;

        }

        private void button1_Click(object sender, RoutedEventArgs e)

        {

            WebClient wbclient = new WebClient();

            wbclient.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);

            wbclient.OpenReadAsync(new Uri("http://ws.geonames.org/postalCodeLookupJSON?postalcode=6600&country=AT"), UriKind.Absolute);

        }

        void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)

        {

            string str = e.Result.ToString();

            var data = new DataContractJsonSerializer(typeof(Postal_Result));

            Postal_Result postal_obj = (Postal_Result)data.ReadObject(e.Result);

            for (int i = 0; i <= postal_obj.addresses.Length - 1; i++)

            {

                PlaceName_combobox.Items.Add(postal_obj.addresses[i].placeName.ToString());

                lat_combobox.Items.Add(postal_obj.addresses[i]. latitude

.ToString());

                lan_combobox.Items.Add(postal_obj.addresses[i]. lngtitude

.ToString());

            }

        }

        private void font_combobox_SelectionChanged(object sender, SelectionChangedEventArgs e)

        {

            if (PlaceName_combobox.SelectedIndex <= 0)

            {

                MessageBox.Show("Wait for Service Resopnse ");

            }

        }

    }

}

Step 6 .Now deploys your application and click on click button to get response of service.

Note : Above code example I used http://ws.geonames.org/postalCodeLookupJSON?postalcode=6600&country=AT  url  as  json web service url , So I am really gives  thanks  provider for providing such url.

Suggestions & queries are welcome!

Thanks’

Jaihind Singh

Vincent IT