MVVM_ContactForm_WP_View

ContactPage.xaml

<phone:PhoneApplicationPage
    x:Class="DemoMvvm.WP.View.ContactPage"
    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"
    xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    mc:Ignorable="d"
    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 Grid.Row="0" Margin="12,17,0,28">
            <TextBlock Text="Contact Me" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
            <TextBlock Text="This is a sample page to demostrate MVVM implementation!" Style="{StaticResource PhoneTextNormalStyle}" TextWrapping="Wrap"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <StackPanel Margin="12,17,0,28">
                <TextBlock Text="Name: " Style="{StaticResource PhoneTextNormalStyle}"/>
                <TextBox Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=Explicit}" TextChanged="OnTextChangeUpdateSource" />

                <TextBlock  Text="Email: " Style="{StaticResource PhoneTextNormalStyle}"/>
                <TextBox Text="{Binding Email, Mode=TwoWay, UpdateSourceTrigger=Explicit}" TextChanged="OnTextChangeUpdateSource" />

                <TextBlock  Text="Category: " Style="{StaticResource PhoneTextNormalStyle}"/>
                <toolkit:ListPicker ItemsSource="{Binding Categories}" SelectedItem="{Binding SelectedCategory, Mode=TwoWay}">
                    <toolkit:ListPicker.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="{Binding Path=Title}" />
                            </StackPanel>
                        </DataTemplate>
                    </toolkit:ListPicker.ItemTemplate>
                </toolkit:ListPicker>

                <TextBlock  Text="Inquiry: " Style="{StaticResource PhoneTextNormalStyle}"/>
                <TextBox  Text="{Binding Path=Inquiry, Mode=TwoWay, UpdateSourceTrigger=Explicit}" 
                          TextChanged="OnTextChangeUpdateSource" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Visible" Height="128"/>

                <Button IsEnabled="{Binding IsValid, Mode=OneWay}" Content="Submit" Command="{Binding SubmitCommand}" />
            </StackPanel>
        </Grid>
    </Grid>

</phone:PhoneApplicationPage>

ContactPage.xaml.cs

public partial class ContactPage : PhoneApplicationPage
{
    private readonly ContactPageViewModel _viewModel;

    public ContactPage()
    {
        this.InitializeComponent();
        this._viewModel = new ContactPageViewModel();
        this.DataContext = this._viewModel;
        this.Loaded += this.OnPageLoaded;
    }

    private void OnPageLoaded(object sender, RoutedEventArgs e)
    {
        this._viewModel.InitializeViewModel();
    }

    private void OnTextChangeUpdateSource(object sender, TextChangedEventArgs e)
    {
        var textBox = sender as TextBox;
        if (textBox != null)
        {
            BindingExpression be = textBox.GetBindingExpression(TextBox.TextProperty);
            be.UpdateSource();
        }
    }
}