title: Binding issue in custom user control
body: <p>I created a usercontrol but I can not make the binding work, I tried in many ways but I did not get it to work, the value is not displayed.</p>
  
  <p><strong>ShowPrice.cs</strong></p>
  
  <pre><code>public static readonly DependencyProperty ValueProperty =
              DependencyProperty.Register("Value", typeof(string), typeof(ShowPrice),
                  new FrameworkPropertyMetadata
                  (
                      string.Empty,
                      FrameworkPropertyMetadataOptions.Journal |
                      FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
                      OnValuePropertyChanged
                  ));
  
      public string Value
      {
          get { return (string)GetValue(ValueProperty); }
          set { SetValue(ValueProperty, value); }
      }
  
      private static void OnValuePropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
      {
          var showPrice = obj as ShowPrice;
          showPrice?.SetValue(ValueProperty, (string)e.NewValue);
      }
  </code></pre>
  
  <p><strong>ShowPrice.xaml</strong></p>
  
  <pre><code>&lt;UserControl x:Class="WPF.CustomControls.UserControls.ShowPrice"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
           DataContext="{Binding RelativeSource={RelativeSource Self}}"&gt;
  
          &lt;TextBlock Text="{Binding Value}"
                     HorizontalAlignment="Center"
                     Foreground="White"
                     FontSize="40"
                     Margin="5" /&gt;
  
  &lt;/UserControl&gt;
  </code></pre>
  
  <p><strong>My view.xaml</strong></p>
  
  <pre><code>&lt;userControls:ShowPrice Value="{Binding MyViewModelProperty, StringFormat=C2, ConverterCulture='es-AR'}"&gt;
  &lt;/userControls:ShowPrice&gt;
  </code></pre>
  
  <p>If I write a value if it works</p>
  
  <pre><code>&lt;userControls:ShowPrice Value="Test"/&gt;
  </code></pre>