title: Windows 8 XAML Databinding on updating on text changed
body: <p>I have a windows 8 XAML/C# application using the MVVM pattern.</p>
  
  <p>All my textboxes on the form have their text properties bound to properties on my MVVM class.</p>
  
  <p>So, one of my textboxes looks like this:</p>
  
  <pre><code>&lt;TextBox x:Name="textAddressLine1" Text="{Binding AddressLine1, Mode=TwoWay}"/&gt;
  </code></pre>
  
  <p>And that property on the MVVM class looks like this:</p>
  
  <pre><code>    private string addressLine1;
  
      public string AddressLine1
      {
          get { return addressLine1; }
          set
          {
              if (addressLine1 == value)
              {
                  return;
              }
  
              addressLine1 = value;
              RaisePropertyChanged("AddressLine1");
          }
      }
  </code></pre>
  
  <p>As I type into my textbox the MVVM class isn't updated. It only gets updated once the focus moves to a different control.</p>
  
  <p>How can I update the MVVM class property when the text changes on my textbox?</p>
  
  <p>Thanks in advance</p>