I have a listbox "listBox\_users" binded to a bindingsource, and another listbox "listBox\_map" which is binded also. I want to drag and drop a user from listBox\_users to listBox\_map.I have done this very well when i delete the bindingsource of listBox\_map.
My problem is that the listBox\_map don't add new items when data source property is defined:

> 
> Items collection cannot be modified when the DataSource property is set.
> 
> 
> 

```
 private void listBox_map_DragDrop(object sender, DragEventArgs e)
    {

        if (e.Data.GetDataPresent(DataFormats.StringFormat))
        {
            string str = listBox_users.Text;

             listBox_map.Items.Add(str); // Error here!
        }

    }

```

How can i add new items to binded listbox?
Thank you.