Datagridcell text change not updating the source in viewmodel.

Hi,

I have created a datagrid with DataGridTextcolumn dynamically. Few columns are read only and few are not. Based on the user action I need to set the read only for a specific cell in data grid. I need to do everything dynamically. For this I have created DataGridTextColumn with read only as false. After that based on user actions and conditions, setting the cell as either editable or not. For that I did like below.

//////////////////////////////////////// Code /////////////////////

 Style style = new Style(typeof(DataGridCell));

            DataTrigger dt = new DataTrigger();
            dt.Binding = new Binding(a_editableBindingPropertyPath);

            ControlTemplate clt = new ControlTemplate();          
            clt.TargetType = typeof(DataGridCell);

            Binding bd2 = new System.Windows.Data.Binding();
            bd2.RelativeSource = new RelativeSource(RelativeSourceMode.TemplatedParent);
            bd2.Path = new PropertyPath("Content.Text");
            bd2.Mode = BindingMode.TwoWay;
            bd2.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;

            FrameworkElementFactory m_borderFWElementFactory = new FrameworkElementFactory(typeof(Border));
            FrameworkElementFactory m_textFWElementFactory = new FrameworkElementFactory(typeof(TextBox));

           
            m_textFWElementFactory.SetBinding(TextBox.TextProperty, bd2);
            m_textFWElementFactory.SetValue(TextBox.IsReadOnlyProperty, false);
            m_textFWElementFactory.SetValue(TextBox.BackgroundProperty, Brushes.White);
           
            m_borderFWElementFactory.AppendChild(m_textFWElementFactory);

            clt.VisualTree = m_borderFWElementFactory;

            Setter s = new Setter(DataGridCell.TemplateProperty, clt);
            dt.Value = "true";

            dt.Setters.Add(s);

            style.Triggers.Add(dt);

            dataGridTextColumn.CellStyle = style;

////////////////////////////////////////

But I am facing one problem. Whenever text in cell changes, its not updating the binding source.

Can somebody suggest me what could be done.

Regards,

Mohan.