Trigger by ScrollPosition

How can Trigger my ManualTrigger with the ScrollPosition of a ScrollViewer?

I have something like this but dont work:

<ManualTrigger ux:Name="MyTrigger">
    <Change Targer="MyScroll.Opacity" Value="1" />
</ManualTrigger>

<ScrollViewer Pointer.Moved="Movement" ux:Name="MyScroll" Opacity="0">

</ScrollViewer>

In Uno:

    void Movement(object sender, PointerMovedArgs args)
    {

     if(MyScroll.ScrollPosition > 100 ){
     MyTrigger.Enable();
     }

    }

Is posible to do something like this?

Something like this?

<ScrollViewer>
    <ScrollRange From="100" To="110">
        <Change Target="MyScroll.Opacity" Value="1">
    </ScrollRange>
</ScrollViewer>

Yes but I need to Disable() a WhileEdgeSwiped in Uno. If the ScrollRange is On, How I put in UNO MyTrigger.Disable();?

To be more specific:

With a WhileEdgeSwiped I show a ScrollViewer, but to go back and hide the WhileEdgeSwiped I want that if the ScrollPosition of the ScrollViewer is between -10 and -20 the WhileEdgeSwiped Disable() to hide the ScrollViewer.

Is posible?

I solved like this!:

    <ScrollViewer Pointer.Moved="MyPointer" Width="100" WidthUnit="Percent" HeightUnit="Percent" Height="100" >

    <ScrollRange ux:Name="MyScrollRange" Inverse="true" From="-100" To="-60">
         <Change Target="MyTrigger.On" Value="true" />
    </ScrollRange>

    <ManualTrigger ux:Name="MyTrigger" />

    </ScrollViewer>

And:

    void MyPointer(object sender, PointerMovedArgs args)
    {
        if(MyTrigger.On == true ){
         MyWhileEdgeSwiped.Disable();
         MyTrigger.On = false;
         }
    } 

i dont know if this is the right way or not…