In this post Matthias
Shapiro discusses the ability to use the StringFormat feature when binding in Silverlight 4.
Previously, if I wanted to have a piece of text that said “Your name is [username]” I could either use the old Horizontal-Stack-Panel-And-2-TextBlocks trick or write a value converter (not going to be seen below because there’s a great example of it over here. Incidentally, that example is totally irrelevant if you’re going to use StringFormat, but more on that in a second).
The StringFormat option in Silverlight 4 allows you put all that information into a single field, which is extremely useful not only for TextBlocks, but for Content fields in a Button. In fact, let’s use that as an example.