how to set the focus state of a textblock in binding in uwp

i am using a textblock whose properties are binded to a binding class, i want the focus textblock to be active on certain times , is there any way to bind the focus state of the textblock?

<TextBox   x:Name="block1" Text="{Binding Text_ , Mode=TwoWay}"  Style="{ThemeResource TextFieldStyle}"  AllowFocusOnInteraction="True" FontSize="14" MinWidth="274" Height="30"  RelativePanel.Below="seperator1" Margin="12 12 12 0" />