Set Default Value for ListBox

Question

In my solution I have set the default value for list like below code

<ListBox x:Name="SelectorList" 
         ItemsSource="{Binding ViewStatusList}"
         SelectedItem="{Binding SelectedDeviceItem,Mode=TwoWay}"        
         IsSynchronizedWithCurrentItem="True">

create the property for SelectedDeviceItem in my view model.

private Device _selecteddeviceitem;
public Device SelectedDeviceItem
{
    get
    {
        return _selecteddeviceitem;
    }
    set
    {
        _selecteddeviceitem = value;
        OnPropertyChanged("SelectedDeviceItem");
    }
}

and passed SelectedDeviceItem = StatusList[0]; in the constructor. But still my listbox will be shown like below.

But I need the result should be like below image

What have I missed in the this list box code?

Are you sure the difference between the two images is not because one of them has focus and the other one does not? In this case use the solution presented [here](http://stackoverflow.com/questions/1356045/set-focus-on-textbox-in-wpf-from-view-model-c) — rmojab63, Feb 22 '17 at 06:31
Listbox selectedIndex="0" it set first item selected . I think you need to set focus for the selected item . — Ragavan, Feb 22 '17 at 06:35

snys98 · Accepted Answer · 2017-06-27T08:58:18.770

I think this could achieve it:

Set the selected ListBoxItem to be focused.

private void ListBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{

    var listbox = sender as ListBox;
    var listboxItem =
        listbox?.ItemContainerGenerator.ContainerFromItem(listbox.SelectedItem) as ListBoxItem;
    listboxItem?.Focus(); 
}

Set focus when the ListBox loaded. This is because that the ListBoxItems may be selected before they are generated.

private void ListBox_Loaded(object sender, RoutedEventArgs e)
{
    var listbox = sender as ListBox;
    var listboxItem =
        listbox?.ItemContainerGenerator.ContainerFromItem(listbox.SelectedItem) as ListBoxItem;
    listboxItem?.Focus();
}

Note that the logic of making item being selected should not be achieved in the view model, it's just kind of a UI logic.

score -1 · Answer 2 · answered Feb 22 '17 at 06:38

-1

it seems ListboxItem not focused . Please Set ListBox to focus and item to focus

listBox.Focus();
var listBoxItem = (ListBoxItem)listBox.ItemContainerGenerator.ContainerFromItem(listBox.SelectedItem);
listBoxItem.Focus();

answered Feb 22 '17 at 06:38

Ragavan

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Setting the focus in MVVM is more difficult. – rmojab63 Feb 22 '17 at 06:46
Not MVVM per-se, but where should this code be placed to achieve the desired results? It does not give that answer. – ΩmegaMan Feb 22 '17 at 18:30

Set Default Value for ListBox

2 Answers2