http://stackoverflow.com/questions/183406/xaml-newline-in-string-attribute
http://www.developerfusion.com/community/blog-entry/8389974/wpf
如果可以写template的话,直接给2个textblock排在一个stackpanel里,或者写<Linebreak>
如果不可以要写hexidecimal 表达换行
<TextBlock Text="Stuff on line1
Stuff on line 2"/>