The format string is intended to work on a DateTime
, not a TimeSpan
.
You could change your code to work with DateTime.Now
instead. Your xaml is fine:
<TextBlock Text="{Binding MyTime,StringFormat=HH:mm}"/>
Update
And from .Net 4 format a TimeSpan
as follows:
<TextBlock Text="{Binding MyTime,StringFormat=hh\\:mm}"/>