ComboBox的默认值？

Question

I'm writing a Windows Store app and I need a ComboBox to have its default value. I also would like to know which item from the list the user selects but I can't find out how to do it. I tried different properties but with no results. Any ideas about doing this?

The code I have for create the ComboBox is:

<ComboBox x:Name="cboxelemento" Width="350" ItemsSource="{Binding}"
        SelectionChanged="cboxelemento_SelectionChanged">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <TextBlock x:Name="lnombre" Text="{Binding Nombre}" FontSize="24"/>
        </DataTemplate>
    </ComboBox.ItemTemplate>
    <ComboBox.DataContext>
        <Clases:Datos/>
    </ComboBox.DataContext>
</ComboBox>

Answer 1

First you must use the SelectedValueChanged Event.

 private void cmbox_SelectedValueChanged(object sender, EventArgs e)
        {
            if (cmbox.Focused)
               {
                  //do

               }
        }

The property Focused goes to true when you have clicked on the ComboBox.

Answer 2

private void cmbox_SelectedValueChanged(object sender, EventArgs e)
{
   var val = cmbox.SelectedValue;
   //or
   //cmbox.Selectedindex;
}

you can access the value like this