title: UWP Combobox binding to SelectedItem property
body: <p>I am trying to get a combobox to work with binding so that I can eventually use it for some settings. I can get the items to populate from an observable collection and bind 'SelectedItem' to a property <code>SelectedItem="{x:Bind SelectedComboBoxOption}"</code></p>
  
  <p>But when I change the selection this is not reflected in the textbox also bound to this property. In the code behind it sets the property once on launch but not when changing items in the combobox. I must be missing something but it is not clear to me what. Any ideas?</p>
  
  <p>This is the XAML:</p>
  
  <pre><code>&lt;Page
  x:Class="ComboBoxTest.MainPage"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:local="using:ComboBoxTest"
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="d"&gt;
  
  &lt;Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"&gt;
      &lt;StackPanel&gt;
          &lt;ComboBox 
              Name="ComboBox" 
              ItemsSource="{x:Bind ComboBoxOptions}" 
              SelectedItem="{x:Bind SelectedComboBoxOption, Mode=TwoWay}" 
              SelectedValuePath="ComboBoxOption" 
              DisplayMemberPath="ComboBoxHumanReadableOption"  
              Header="ComboBox" &gt;
          &lt;/ComboBox&gt;
          &lt;TextBlock Name="BoundTextblock" Text="{x:Bind SelectedComboBoxOption}"/&gt;
      &lt;/StackPanel&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p></p>
  
  <p>And this is the code behind:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Collections.ObjectModel;
  using System.ComponentModel;
  using System.IO;
  using System.Linq;
  using System.Runtime.InteropServices.WindowsRuntime;
  using Windows.Foundation;
  using Windows.Foundation.Collections;
  using Windows.UI.Xaml;
  using Windows.UI.Xaml.Controls;
  using Windows.UI.Xaml.Controls.Primitives;
  using Windows.UI.Xaml.Data;
  using Windows.UI.Xaml.Input;
  using Windows.UI.Xaml.Media;
  using Windows.UI.Xaml.Navigation;
  
  
  
  namespace ComboBoxTest
  {
  
   public sealed partial class MainPage : Page, INotifyPropertyChanged
   {
  
      private ObservableCollection&lt;ComboBoxItem&gt; ComboBoxOptions;
  
      public MainPage()
      {
          this.InitializeComponent();
          ComboBoxOptions = new ObservableCollection&lt;ComboBoxItem&gt;();
          ComboBoxOptionsManager.GetComboBoxList(ComboBoxOptions);
      }
  
      public class ComboBoxItem
      {
          public string ComboBoxOption { get; set; }
          public string ComboBoxHumanReadableOption { get; set; }
      }
  
      public class ComboBoxOptionsManager
      {
          public static void GetComboBoxList(ObservableCollection&lt;ComboBoxItem&gt; ComboBoxItems)
          {
              var allItems = getComboBoxItems();
              ComboBoxItems.Clear();
              allItems.ForEach(p =&gt; ComboBoxItems.Add(p));
          }
  
          private static List&lt;ComboBoxItem&gt; getComboBoxItems()
          {
              var items = new List&lt;ComboBoxItem&gt;();
  
              items.Add(new ComboBoxItem() { ComboBoxOption = "Option1", ComboBoxHumanReadableOption = "Option 1" });
              items.Add(new ComboBoxItem() { ComboBoxOption = "Option2", ComboBoxHumanReadableOption = "Option 2" });
              items.Add(new ComboBoxItem() { ComboBoxOption = "Option3", ComboBoxHumanReadableOption = "Option 3" });
  
              return items;
          }
      }
  
  
      string _SelectedComboBoxOption = "Option1";
      public string SelectedComboBoxOption
      {
          get
          {
              return _SelectedComboBoxOption;
          }
          set
          {
              if (_SelectedComboBoxOption != value)
              {
                  _SelectedComboBoxOption = value;
                  RaisePropertyChanged("SelectedComboBoxOption");
              }
          }
      }
  
      void RaisePropertyChanged(string prop)
      {
          if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(prop)); }
      }
      public event PropertyChangedEventHandler PropertyChanged;
   }
  }
  </code></pre>