Wpf Replace Selected List items

Question

I have this Lists here. I want to be able to Select one Object on the left and one on the right, then click the button and it shoudl change them on click.

private void substituteBtn_Click(object sender, RoutedEventArgs e)
{
   object temp = startingLbx.SelectedItem;
   startingLbx.SelectedItem = benchLbx.SelectedItem.ToString();
   benchLbx.SelectedItem = temp.ToString();
}

I have this code to change it. I tried several fixes, but I couldn't find the answer to why my lists are not changing at all after the press of the button. Do I have to change something in the code? Is it because of something in the XAML? I would be happy if someone could help

Answer 1

Here is how you could swap the items directly in the Items collection:

private void substituteBtn_Click(object sender, RoutedEventArgs e)
{
    object temp = startingLbx.SelectedItem;
    startingLbx.Items[startingLbx.SelectedIndex] = benchLbx.SelectedItem;
    benchLbx.Items[benchLbx.SelectedIndex] = temp;
}

If you're using the ItemsSource property, you should swap the items in the source collections.

Answer 2

SelectedItem only works if the object exist in the list, if not, the SelectedIndex property is left at its current value.

Something like this should do the trick:

        object tempStarting = startingLbx.SelectedItem;
        object tempbench = benchLbx.SelectedItem;

        startingLbx.Items.Remove(tempStarting);
        benchLbx.Items.Remove(tempbench);

        startingLbx.Items.Add(tempbench);
        benchLbx.Items.Add(tempStarting);
        

        startingLbx.SelectedItem = tempbench;
        benchLbx.SelectedItem = tempStarting;

In the case you want to have the same position in the list

        object tempStarting = startingLbx.SelectedItem;
        object tempbench = benchLbx.SelectedItem;
        int indexStarting = startingLbx.SelectedIndex;
        int indexbench = benchLbx.SelectedIndex;

        startingLbx.Items.Remove(tempStarting);
        benchLbx.Items.Remove(tempbench);

        startingLbx.Items.Insert(indexStarting, tempbench);
        benchLbx.Items.Insert(indexbench,tempStarting);
        
        startingLbx.SelectedItem = tempbench;
        benchLbx.SelectedItem = tempStarting;

I did not test this code but you will get the idea.