private void handleListFilterType()
        {
            if (FilterCurrentData.Type == FilterType.List)
            {
                ComboBox comboBox             = this.Template.FindName("PART_ComboBoxFilter", this) as ComboBox;
                DataGridComboBoxColumn column = AssignedDataGridColumn as DataGridComboBoxColumn;

                if (comboBox != null && column != null)
                {
                    if (DataGridComboBoxExtensions.GetIsTextFilter(column))
                    {
                        FilterCurrentData.Type = FilterType.Text;
                        initControlType();
                    }
                    else //list filter type
                    {
                        Binding columnItemsSourceBinding = null;
                        columnItemsSourceBinding = BindingOperations.GetBinding(column, DataGridComboBoxColumn.ItemsSourceProperty);

                        if (columnItemsSourceBinding == null)
                        {
                            System.Windows.Setter styleSetter = column.EditingElementStyle.Setters.First(s => ((System.Windows.Setter)s).Property == DataGridComboBoxColumn.ItemsSourceProperty) as System.Windows.Setter;
                            if (styleSetter != null)
                            {
                                columnItemsSourceBinding = styleSetter.Value as Binding;
                            }
                        }

                        comboBox.DisplayMemberPath = column.DisplayMemberPath;
                        comboBox.SelectedValuePath = column.SelectedValuePath;

                        if (columnItemsSourceBinding != null)
                        {
                            BindingOperations.SetBinding(comboBox, ComboBox.ItemsSourceProperty, columnItemsSourceBinding);
                        }

                        comboBox.RequestBringIntoView
                            += new RequestBringIntoViewEventHandler(setComboBindingAndHanldeUnsetValue);
                    }
                }
            }
        }
        private string getValuePropertyBindingPath(DataGridColumn column)
        {
            string path = String.Empty;

            if (column is DataGridBoundColumn)
            {
                DataGridBoundColumn bc = column as DataGridBoundColumn;
                // VIKRAM: Added support for MultiBindings
                if (bc.Binding is Binding)
                {
                    path = (bc.Binding as Binding).Path.Path;
                }
                else
                {
                    // assume Multibinding with data as the first binding
                    path = ((bc.Binding as MultiBinding).Bindings[0] as Binding).Path.Path;
                }
                // END VIKRAM
            }
            else if (column is DataGridTemplateColumn)
            {
                DataGridTemplateColumn tc = column as DataGridTemplateColumn;

                object templateContent = tc.CellTemplate.LoadContent();

                if (templateContent != null && templateContent is TextBlock)
                {
                    TextBlock block = templateContent as TextBlock;

                    BindingExpression binding = block.GetBindingExpression(TextBlock.TextProperty);

                    path = binding.ParentBinding.Path.Path;
                }
            }
            else if (column is DataGridComboBoxColumn)
            {
                DataGridComboBoxColumn comboColumn = column as DataGridComboBoxColumn;

                path = null;

                Binding binding = ((comboColumn.SelectedValueBinding) as Binding);

                if (binding == null)
                {
                    binding = ((comboColumn.SelectedItemBinding) as Binding);
                }

                if (binding == null)
                {
                    binding = comboColumn.SelectedValueBinding as Binding;
                }

                if (binding != null)
                {
                    path = binding.Path.Path;
                }

                if (comboColumn.SelectedItemBinding != null && comboColumn.SelectedValueBinding == null)
                {
                    if (path != null && path.Trim().Length > 0)
                    {
                        if (DataGridComboBoxExtensions.GetIsTextFilter(comboColumn))
                        {
                            path += "." + comboColumn.DisplayMemberPath;
                        }
                        else
                        {
                            path += "." + comboColumn.SelectedValuePath;
                        }
                    }
                }
            }

            return(path);
        }