Simple MVVM - Looking for example of a user registration page - silverlight

Question

I am new to Silverlight and have been working with Simple MVVM to create a learning app. The Simple MVVM author provides several good examples of list/detail data binding but I'm looking an example of a screen to register a user. Since this is an internal app I can pass in the Windows ID from the hosting website and check it against the user database. If the user ID does not exist I would like to display a registration where the user can enter their first/last name and click a "register" button to save a new user record. Seems like a simple pattern but I haven't been able to figure it out.

Answer 1

Well I managed to combine a few different examples and come up with an example that works. This is part of a learning application that I am creating. It allows users (in my IT department) to suggest and vote for lunch destinations. For this app, the diner is the user. The code below will display a screen with the user's windows ID (read only) and inputs for first/last name in addition to a "register" button.
XAML (registerdinerview.xaml):
<navigation:Page x:Class="LTDestination.Views.RegisterDinerView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"
xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
d:DesignWidth="640"
d:DesignHeight="480"
Title="RegisterDinerView Page"
DataContext="{Binding Source={StaticResource Locator}, Path=RegisterDinerViewModel}"
>
<navigation:Page.Resources>
<Style TargetType="Button">
<Style.Setters>
<Setter Property="Height" Value="23"/>
<Setter Property="Width" Value="60"/>
<Setter Property="Margin" Value="5,0,0,0"/>
</Style.Setters>
</Style>
</navigation:Page.Resources>
<StackPanel x:Name="LayoutRoot">
<StackPanel x:Name="ContentStackPanel">
<TextBlock x:Name="HeaderText" Style="{StaticResource HeaderTextStyle}" Text="New User Registration"/>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<sdk:Label Content="User Id:" Grid.Row="0" />
<TextBlock Grid.Row="0" Grid.Column="1" Height="30" Text="{Binding Path=Model.UserId}" />
<sdk:Label Content="First Name:" Grid.Row="1" />
<TextBox Grid.Row="1" Grid.Column="1" Height="30" Text="{Binding Path=Model.FirstName, Mode=TwoWay}" />
<sdk:Label Content="Last Name:" Grid.Row="2" />
<TextBox Grid.Row="2" Grid.Column="1" Height="30" Text="{Binding Path=Model.LastName, Mode=TwoWay}" />
<Button x:Name="RegisterButton" Content="Register" Click="registerButton_Click"
Grid.Row="3" Grid.Column="1" Height="23" Width="75" HorizontalAlignment="Left" Margin="5,0,0,0"/>
</Grid>
</StackPanel>
</StackPanel>
View Code behind (registerdinerview.xaml.cs):
namespace LTDestination.Views
{
public partial class RegisterDinerView : Page
{
RegisterDinerViewModel _ViewModel;
public RegisterDinerView()
{
InitializeComponent();
_ViewModel = (RegisterDinerViewModel)DataContext;
_ViewModel.NewDiner();
}
private void registerButton_Click(object sender, RoutedEventArgs e)
{
_ViewModel.SaveChanges();
}
// Executes when the user navigates to this page.
protected override void OnNavigatedTo(NavigationEventArgs e)
{
}
}
}
ViewModel:
using System;
using System.Collections.Generic;
// Toolkit namespace
using LTDestination.Services;
using LTDestination.Web;
using SimpleMvvmToolkit;
namespace LTDestination.ViewModels
{
///
/// This class extends ViewModelDetailBase which implements IEditableDataObject.
///
/// Specify type being edited DetailType as the second type argument
/// and as a parameter to the seccond ctor.
///
///
/// Use the mvvmprop snippet to add bindable properties to this ViewModel.
///
///
public class RegisterDinerViewModel : ViewModelDetailBase
{
#region Initialization and Cleanup
private IDinerServiceAgent serviceAgent;
public RegisterDinerViewModel()
{
}
public RegisterDinerViewModel(IDinerServiceAgent serviceAgent)
{
this.serviceAgent = serviceAgent;
}
#endregion
#region Notifications
public event EventHandler<NotificationEventArgs<Exception>> ErrorNotice;
#endregion
#region Properties
private bool _IsBusy;
public bool IsBusy
{
get { return _IsBusy; }
set
{
_IsBusy = value;
NotifyPropertyChanged(m => m.IsBusy);
}
}
#endregion
#region Methods
public void NewDiner()
{
serviceAgent.GetDiners(DinersLoaded);
}
public void SaveChanges()
{
serviceAgent.AddDiner(base.Model);
serviceAgent.SaveChanges(DinerSaved);
IsBusy = true;
}
#endregion
#region Completion Callbacks
private void DinersLoaded(List<Diner> entities, Exception error)
{
// If no error is returned, set the model to entities
if (error == null)
{
base.Model = new Diner { UserId = App.UserId, Active = true };
}
// Otherwise notify view that there's an error
else
{
NotifyError("Unable to retrieve items", error);
}
// We're done
IsBusy = false;
}
private void DinerSaved(Exception error)
{
if (error != null)
{
NotifyError("Unable to save diner", error);
}
else
{
MessageBus.Default.Notify(MessageTokens.Navigation, this, new NotificationEventArgs(PageNames.Home));
}
}
#endregion
#region Helpers
// Helper method to notify View of an error
private void NotifyError(string message, Exception error)
{
// Notify view of an error
Notify(ErrorNotice, new NotificationEventArgs<Exception>(message, error));
}
#endregion
}
}