My preference is to use Environment.NewLine
directly:
<MultiBinding StringFormat="So and so will donate {0:C0}{3}to {1}, bringing the{3}total amount to {2:C0}.">
<Binding Path="VisitorTotal" />
<Binding Path="EventName" />
<Binding Path="EventTotal" />
<Binding Source="{x:Static System:Environment.NewLine}"/>
</MultiBinding>
However, you'll also need to make sure the TextBlock.TextWrapping
is set appropriately.