New Post: IntegerUpDown In DataGrid.CellEditTemplate Can not selectAll

<DataGridTemplateColumn.CellEditingTemplate>
                        <DataTemplate>
                            <Grid Background="AliceBlue" FocusManager.FocusedElement="{Binding ElementName=intUpDown}">
                                <xwt:IntegerUpDown Value="{Binding Age}" Name="intUpDown" SelectAllOnGotFocus="True" GotFocus="intUpDown_GotFocus">
                                </xwt:IntegerUpDown>
                            </Grid>
                        </DataTemplate>
 </DataGridTemplateColumn.CellEditingTemplate>

Hi:
I tried set 'SelectAllOnGotFocus' true and 'AutoSelectBehavior' OnFocus, but it doesn't work.
Is there any method which I can use to select all programmatically?
Do you have any idea?
Thanks in advance.