public class FullName
{
    public string FirstName { get; set; }
    public char MiddleInitial { get; set; }
    public string LastName { get; set; }
}

public partial class WorkingWithTemplates : Window
{
    // This is the Window's constructor.
    public WorkingWithTemplates()
    {
        InitializeComponent();

        base.DataContext = new FullName[]
        {
            new FullName 
            { 
                FirstName = "Johann", 
                MiddleInitial = 'S', 
                LastName = "Bach" 
            },
            new FullName 
            { 
                FirstName = "Gustav",
                MiddleInitial = ' ',
                LastName = "Mahler" 
            },
            new FullName 
            { 
                FirstName = "Alfred", 
                MiddleInitial = 'G', 
                LastName = "Schnittke" 
            }
        };
    }
}

<!-- This displays the FullName objects. -->
<ItemsControl ItemsSource="{Binding Path=.}">
  <ItemsControl.ItemTemplate>
    <DataTemplate>
      <StackPanel Orientation="Horizontal">
        <TextBlock FontWeight="Bold" Text="{Binding LastName}" />
        <TextBlock Text=", " />
        <TextBlock Text="{Binding FirstName}" />
        <TextBlock Text=" " />
        <TextBlock Text="{Binding MiddleInitial}" />
      </StackPanel>
    </DataTemplate>
  </ItemsControl.ItemTemplate>
</ItemsControl>

<XmlDataProvider x:Key="xmlData">
  <x:XData>
    <customers >
      <customer name="Customer 1">
        <order desc="Big Order">
          <orderDetail product="Glue" quantity="21" />
          <orderDetail product="Fudge" quantity="32" />
          </order>
          <order desc="Little Order">
            <orderDetail product="Ham" quantity="1" />
            <orderDetail product="Yarn" quantity="2" />
          </order>
        </customer>
        <customer name="Customer 2">
          <order desc="First Order">
            <orderDetail product="Mousetrap" quantity="4" />
          </order>
        </customer>
      </customers>
    </x:XData>
</XmlDataProvider>

<Grid DataContext=
    "{Binding Source={StaticResource xmlData},
    XPath=customers/customer}"
    Margin="4" 
  >
  <Grid.RowDefinitions>
    <RowDefinition Height="Auto" />
    <RowDefinition />
    <RowDefinition />
  </Grid.RowDefinitions>

  <!-- CUSTOMERS -->
  <DockPanel Grid.Row="0">
    <TextBlock DockPanel.Dock="Top" FontWeight="Bold" Text="Customers" />
    <ComboBox
      IsSynchronizedWithCurrentItem="True"
      ItemsSource="{Binding}"
      >
      <ComboBox.ItemTemplate>
        <DataTemplate>
          <TextBlock Text="{Binding XPath=@name}" />
        </DataTemplate>
      </ComboBox.ItemTemplate>
    </ComboBox>
  </DockPanel>

  <!-- ORDERS -->
  <DockPanel Grid.Row="1">
    <TextBlock DockPanel.Dock="Top" FontWeight="Bold" Text="Orders" />
    <ListBox
      x:Name="orderSelector" 
      DataContext="{Binding Path=CurrentItem}"
      IsSynchronizedWithCurrentItem="True" 
      ItemsSource="{Binding XPath=order}"
      >
      <ListBox.ItemTemplate>
        <DataTemplate>
          <TextBlock Text="{Binding XPath=@desc}" />
        </DataTemplate>
      </ListBox.ItemTemplate>
    </ListBox>
  </DockPanel>

  <!-- ORDER DETAILS -->
  <DockPanel Grid.Row="2">
    <TextBlock DockPanel.Dock="Top" FontWeight="Bold" 
      Text="Order Details" />
    <ItemsControl 
      DataContext=
         "{Binding ElementName=orderSelector, Path=SelectedItem}"
      ItemsSource="{Binding XPath=orderDetail}">
      <ItemsControl.ItemTemplate>
        <DataTemplate>
          <TextBlock>
            <Run>Product:</Run>
            <TextBlock Text="{Binding XPath=@product}" />
            <Run>(</Run>
            <TextBlock Text="{Binding XPath=@quantity}" />
            <Run>)</Run>
          </TextBlock>
        </DataTemplate>
      </ItemsControl.ItemTemplate>
    </ItemsControl>
  </DockPanel>
</Grid>

public class Customer
{
    public string Name { get; set; }
    public List<Order> Orders { get; set; }

    public override string ToString()
    {
        return this.Name;
    }
}

public class Order
{
    public string Desc { get; set; }
    public List<OrderDetail> OrderDetails { get; set; }

    public override string ToString()
    {
        return this.Desc;
    }
}

public class OrderDetail
{
    public string Product { get; set; }
    public int Quantity { get; set; }
}

<Grid Margin="4">
  <Grid.RowDefinitions>
    <RowDefinition Height="Auto" />
    <RowDefinition />
    <RowDefinition />
  </Grid.RowDefinitions>

   <!-- CUSTOMERS -->
   <DockPanel Grid.Row="0">
     <TextBlock DockPanel.Dock="Top" FontWeight="Bold" Text="Customers"
     />
     <ComboBox 
       IsSynchronizedWithCurrentItem="True" 
       ItemsSource="{Binding Path=.}" 
       />
   </DockPanel>

   <!-- ORDERS -->
   <DockPanel Grid.Row="1">
     <TextBlock DockPanel.Dock="Top" FontWeight="Bold" Text="Orders" />
     <ListBox 
       IsSynchronizedWithCurrentItem="True" 
       ItemsSource="{Binding Path=CurrentItem.Orders}" 
       />
   </DockPanel>

   <!-- ORDER DETAILS -->
   <DockPanel Grid.Row="2">
     <TextBlock DockPanel.Dock="Top" FontWeight="Bold" 
        Text="Order Details" />
     <ItemsControl
       ItemsSource="{Binding Path=CurrentItem.Orders.CurrentItem.
       OrderDetails}"
       >
       <ItemsControl.ItemTemplate>
         <DataTemplate>
           <TextBlock>
             <Run>Product:</Run>
             <TextBlock Text="{Binding Path=Product}" />
             <Run>(</Run>
             <TextBlock Text="{Binding Path=Quantity}" />
             <Run>)</Run>
           </TextBlock>
         </DataTemplate>
       </ItemsControl.ItemTemplate>
     </ItemsControl>
   </DockPanel>
</Grid>

<Grid>
  <Grid.DataContext>
    <!-- 
    This sets the DataContext of the UI
    to a Customers returned by calling
    the static CreateCustomers method. 
    -->
    <ObjectDataProvider 
      xmlns:local="clr-namespace:VariousBindingExamples"
      ObjectType="{x:Type local:Customer}"
      MethodName="CreateCustomers"
      />
  </Grid.DataContext>

  <Grid.Resources>
    <!-- ORDER DETAIL TEMPLATE -->
    <DataTemplate x:Key="OrderDetailTemplate">
      <TextBlock>
        <Run>Product:</Run>
        <TextBlock Text="{Binding Path=Product}" />
        <Run>(</Run>
        <TextBlock Text="{Binding Path=Quantity}" />
        <Run>)</Run>
      </TextBlock>
    </DataTemplate>

    <!-- ORDER TEMPLATE -->
    <HierarchicalDataTemplate 
      x:Key="OrderTemplate"
      ItemsSource="{Binding Path=OrderDetails}"
      ItemTemplate="{StaticResource OrderDetailTemplate}"
      >
      <TextBlock Text="{Binding Path=Desc}" />
    </HierarchicalDataTemplate>

    <!-- CUSTOMER TEMPLATE -->
    <HierarchicalDataTemplate 
      x:Key="CustomerTemplate"
      ItemsSource="{Binding Path=Orders}"
      ItemTemplate="{StaticResource OrderTemplate}"
      >
      <TextBlock Text="{Binding Path=Name}" />
    </HierarchicalDataTemplate>
  </Grid.Resources>

  <TreeView
    ItemsSource="{Binding Path=.}"
    ItemTemplate="{StaticResource CustomerTemplate}"
    />

</Grid>

<!-- START DATE -->
<TextBlock Grid.Row="0">Start Date:</TextBlock>
<TextBox Grid.Row="1">
  <TextBox.Text>
    <Binding Path="StartDate" UpdateSourceTrigger="PropertyChanged">
      <Binding.ValidationRules>
        <ExceptionValidationRule />
      </Binding.ValidationRules>
    </Binding>
  </TextBox.Text>
</TextBox>

<!-- DURATION -->
<TextBlock Grid.Row="2">Duration:</TextBlock>
<TextBox 
  Grid.Row="3" 
  Text="{Binding 
         Path=Duration, 
         UpdateSourceTrigger=PropertyChanged, 
         ValidatesOnExceptions=True}" 
  />

<!-- 
The template which renders a TextBox 
when it contains invalid data. 
-->
<ControlTemplate x:Key="TextBoxErrorTemplate">
  <DockPanel>
    <Ellipse 
      DockPanel.Dock="Right" 
      Margin="2,0"
      ToolTip="Contains invalid data"
      Width="10" Height="10"   
      >
      <Ellipse.Fill>
        <LinearGradientBrush>
          <GradientStop Color="#11FF1111" Offset="0" />
          <GradientStop Color="#FFFF0000" Offset="1" />
        </LinearGradientBrush>
      </Ellipse.Fill>
    </Ellipse>
    <!-- 
    This placeholder occupies where the TextBox will appear. 
    -->
    <AdornedElementPlaceholder />
  </DockPanel>
</ControlTemplate>

<!-- 
The Style applied to both TextBox controls in the UI.
-->
<Style TargetType="TextBox">
  <Setter Property="Margin" Value="4,4,10,4" />
  <Setter 
    Property="Validation.ErrorTemplate" 
    Value="{StaticResource TextBoxErrorTemplate}" 
    />
  <Style.Triggers>
    <Trigger Property="Validation.HasError" Value="True">
      <Setter Property="ToolTip">
        <Setter.Value>
          <Binding 
            Path="(Validation.Errors)[0].ErrorContent"
            RelativeSource="{x:Static RelativeSource.Self}"
            />
        </Setter.Value>
      </Setter>
    </Trigger>
  </Style.Triggers>
</Style>

public class SmartEra 
    : System.ComponentModel.IDataErrorInfo
{
    public DateTime StartDate { get; set; }
    public TimeSpan Duration { get; set; }

    #region IDataErrorInfo Members

    public string Error
    {
        get { return null; }
    }

    public string this[string property]
    {
        get 
        {
            string msg = null;
            switch (property)
            {
                case "StartDate":
                    if (DateTime.Now < this.StartDate)
                        msg = "Start date must be in the past.";
                    break;

                case "Duration":
                    if (this.Duration.Ticks == 0)
                        msg = "An era must have a duration.";
                    break;

                default:
                    throw new ArgumentException(
                        "Unrecognized property: " + property);
            }
            return msg;
        }
    }

    #endregion // IDataErrorInfo Members
}

<!-- START DATE -->
<TextBlock Grid.Row="0">Start Date:</TextBlock>
<TextBox Grid.Row="1">
  <TextBox.Text>
    <Binding Path="StartDate" UpdateSourceTrigger="PropertyChanged">
      <Binding.ValidationRules>
        <ExceptionValidationRule />
        <DataErrorValidationRule />
      </Binding.ValidationRules>
    </Binding>
  </TextBox.Text>
</TextBox>

<!-- DURATION -->
<TextBlock Grid.Row="2">Duration:</TextBlock>
<TextBox 
  Grid.Row="3" 
  Text="{Binding 
         Path=Duration, 
         UpdateSourceTrigger=PropertyChanged, 
         ValidatesOnDataErrors=True,
         ValidatesOnExceptions=True}" 
  />