在MVVM中获取列表框SelectedValue

Question

I have a MainWindow that contains A listbox, and a ContentControl, each time you select something from the Listbox, the ContentControl will display something else.

   <ContentControl Content="{Binding ElementName=SomeList, Path=SelectedItem.Content}" />

  <ListBox  x:Name="SomeList" Margin="0 16 0 16" SelectedIndex="0"  SelectedValue="{Binding X}"            
                         ItemsSource="{Binding DemoItems}">

ViewModel:

 private string _X;
    public string X

    {
        get { return _X; }
        set
        {
            _X = value;
            NotifyOfPropertyChange("X");
        }
    }

Trying to display X will result in the same thing:

namespace.DemoItem

DemoItem.cs:

 public class DemoItem : INotifyPropertyChanged
{
    private object _icon;
    private string _name;
    private object _content;
    private Thickness _marginRequirement;

    public DemoItem(object icon, string name, object content, Thickness margin,  IEnumerable<DocumentationLink> documentation)
    {
        _icon = icon;
        _name = name;
        Content = content;
        _marginRequirement = margin;

        Documentation = documentation;
    }
} 

So how is it possible to only get the name?

Answer 1

Data binding only works with public properties. So add a Name property

public class DemoItem : INotifyPropertyChanged
{
    ...
    public string Name { get { return _name; } }
}

Assuming that yous intention is to selected a DemoItem by its Name , you should also set the ListBox's SelectedValuePath in conjunction with SelectedValue :

<ListBox ItemsSource="{Binding DemoItems}"
         SelectedValuePath="Name"
         SelectedValue="{Binding X}" />

Then simply display the selected item's Name like this:

<TextBlock Text="{Binding X}" />