data grid row button is not fire on single click.

When I fill the details and bind those in data grid, then I have to fire the click event on edit button click in the row of data grid. Unable to do this in single click, but it fires on the second click.

I have used following code:

<DataGridTemplateColumn.CellTemplate><DataTemplate><StackPanel><Button Grid.Row="1" Name="PreviewNotificationPopup"
                                                                            Click="PreviewNotificationPopup_Click" 
                                                                            VerticalAlignment="Center" HorizontalAlignment="Center" IsEnabled="True" Style="{StaticResource addBtn}"><Image Source="Resources/preview.png" Width="24"/></Button></StackPanel></DataTemplate></DataGridTemplateColumn.CellTemplate>