TextLineBounds snipping bottom of letters

问题

I'm using TextLineBounds in Windows 8.1 to align text of different font sizes on the baseline, such as

With the XAML looking like:

    <Grid x:Name="PageHeader">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="28" />
        </Grid.RowDefinitions>

        <Grid Grid.Row="0">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="15" />
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="15" />
                <ColumnDefinition Width="Auto" />
            </Grid.ColumnDefinitions>
            <TextBlock Grid.Column="1"
                       VerticalAlignment="Bottom"
                       TextLineBounds="TrimToBaseline"
                       FontSize="50"
                       Text="OOO Big Font" />
            <TextBlock Grid.Column="3"
                       VerticalAlignment="Bottom"
                       TextLineBounds="TrimToBaseline"
                       FontSize="26"
                       Text="OOO SmallerFont" />
            <TextBlock Grid.Column="5"
                       VerticalAlignment="Bottom"
                       TextLineBounds="TrimToBaseline"
                       FontSize="20"
                       Text="OOO Even Smaller Font" />
        </Grid>
     </Grid>

When I resize the window, at some point (before the minimum size of 500) the descenders are clipped (and I've also seen the bottom pixel or two across entire line get clipped even when there are no descenders - resulting in artifacts like a flattened O).

The display elements do not change on the resize, there's no modification due to visual state, etc.

It seems like a bug, but not sure if there's a workaround (other than to abandon use of TextLineBounds).

来源：https://stackoverflow.com/questions/27829414/textlinebounds-snipping-bottom-of-letters