DragDropXAMLExample.xaml

<Grid AllowDrop="True" DragOver="OnFileDragOver" DragLeave="OnFileDragLeave" Drop="OnFileDrop">
    <GridView x:Name="FileList" ItemsSource="{Binding Files}" IsItemClickEnabled="True" SelectionMode="None" />

    <RelativePanel x:Name="AddFilePanel" Background="#44000000" Visibility="Collapsed">
        <SymbolIcon x:Name="AddSymbol" Symbol="Add" RelativePanel.AlignVerticalCenterWithPanel="True" RelativePanel.AlignHorizontalCenterWithPanel="True" Foreground="White" RenderTransformOrigin="0.5,0.5">
            <SymbolIcon.RenderTransform>
                <CompositeTransform ScaleX="1.5" ScaleY="1.5"/>
            </SymbolIcon.RenderTransform>
        </SymbolIcon>

        <TextBlock RelativePanel.Below="AddSymbol" RelativePanel.AlignHorizontalCenterWithPanel="True" Margin="0,12,0,0" Text="Add file to view" Foreground="White" FontSize="24"></TextBlock>
    </RelativePanel>
</Grid>