停止按钮导致列表框取消选择

Question

I have a button in place so that when I click it, it deletes the selected ListItem from the ListBox called listBoxNames and removes the selected Person object from a list named people .

However, after clicking the delete button an error message pops up telling me that the index is out of range. This leads me to believe that upon clicking the button, it has deselected the ListBox and so listBoxNames.SelectedIndex returns -1.

Is there anyway around this or have I made some stupid mistake?

private void deleteEntryBtn_Click(object sender, RoutedEventArgs e)
    {
        try
        {
            listBoxNames.Items.Remove(listBoxNames.SelectedItems[0]);
            people.RemoveAt(listBoxNames.SelectedIndex);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

Answer 1

Your code removes the selected item.
Once that item isn't there, there is no selection.

You need to check which item is selected before removing it.

Answer 2

Try this instead:

private void deleteEntryBtn_Click(object sender, RoutedEventArgs e)
{
    try
    {
        people.RemoveAt(listBoxNames.SelectedIndex);
        listBoxNames.RemoveAt(listBoxNames.SelectedIndex);
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}