richTextBox1.DataBindings.Add("Text", bindingSource1, "nameColumn", true, DataSourceUpdateMode.OnPropertyChanged);

bindingSource1.BindingComplete += new BindingCompleteEventHandler(bindingSource1_BindingComplete);  
 
private void bindingSource1_BindingComplete(object sender, BindingCompleteEventArgs e)
        {
            if (e.BindingCompleteContext == BindingCompleteContext.DataSourceUpdate && e.Exception == null)
                e.Binding.BindingManagerBase.EndCurrentEdit();
        }